diff --git a/Marlin/Configuration_adv.h b/Marlin/Configuration_adv.h
index 8cdd7f5d06..bf37fe1eea 100644
--- a/Marlin/Configuration_adv.h
+++ b/Marlin/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/default/Configuration_adv.h b/Marlin/src/config/default/Configuration_adv.h
index 8cdd7f5d06..bf37fe1eea 100644
--- a/Marlin/src/config/default/Configuration_adv.h
+++ b/Marlin/src/config/default/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/3DFabXYZ/Migbot/Configuration_adv.h b/Marlin/src/config/examples/3DFabXYZ/Migbot/Configuration_adv.h
index 7278321821..90674661d7 100644
--- a/Marlin/src/config/examples/3DFabXYZ/Migbot/Configuration_adv.h
+++ b/Marlin/src/config/examples/3DFabXYZ/Migbot/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/AlephObjects/TAZ4/Configuration_adv.h b/Marlin/src/config/examples/AlephObjects/TAZ4/Configuration_adv.h
index f3a3b701f9..a9ed5c838d 100644
--- a/Marlin/src/config/examples/AlephObjects/TAZ4/Configuration_adv.h
+++ b/Marlin/src/config/examples/AlephObjects/TAZ4/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Anet/A2/Configuration_adv.h b/Marlin/src/config/examples/Anet/A2/Configuration_adv.h
index bdcb981bc4..35b30313f2 100644
--- a/Marlin/src/config/examples/Anet/A2/Configuration_adv.h
+++ b/Marlin/src/config/examples/Anet/A2/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Anet/A2plus/Configuration_adv.h b/Marlin/src/config/examples/Anet/A2plus/Configuration_adv.h
index bdcb981bc4..35b30313f2 100644
--- a/Marlin/src/config/examples/Anet/A2plus/Configuration_adv.h
+++ b/Marlin/src/config/examples/Anet/A2plus/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Anet/A6/Configuration_adv.h b/Marlin/src/config/examples/Anet/A6/Configuration_adv.h
index 3431b89822..bef3af95ed 100644
--- a/Marlin/src/config/examples/Anet/A6/Configuration_adv.h
+++ b/Marlin/src/config/examples/Anet/A6/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 10    // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Anet/A8/Configuration_adv.h b/Marlin/src/config/examples/Anet/A8/Configuration_adv.h
index 56df31fc22..94ddc4f5c4 100644
--- a/Marlin/src/config/examples/Anet/A8/Configuration_adv.h
+++ b/Marlin/src/config/examples/Anet/A8/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 10    // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/AnyCubic/i3/Configuration_adv.h b/Marlin/src/config/examples/AnyCubic/i3/Configuration_adv.h
index e49b4ecd67..5c9d22308f 100644
--- a/Marlin/src/config/examples/AnyCubic/i3/Configuration_adv.h
+++ b/Marlin/src/config/examples/AnyCubic/i3/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/ArmEd/Configuration_adv.h b/Marlin/src/config/examples/ArmEd/Configuration_adv.h
index 2d19ad6372..97023bbb20 100644
--- a/Marlin/src/config/examples/ArmEd/Configuration_adv.h
+++ b/Marlin/src/config/examples/ArmEd/Configuration_adv.h
@@ -82,6 +82,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/BIBO/TouchX/cyclops/Configuration_adv.h b/Marlin/src/config/examples/BIBO/TouchX/cyclops/Configuration_adv.h
index b992e9a78e..57a9767dfd 100644
--- a/Marlin/src/config/examples/BIBO/TouchX/cyclops/Configuration_adv.h
+++ b/Marlin/src/config/examples/BIBO/TouchX/cyclops/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 2     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/BIBO/TouchX/default/Configuration_adv.h b/Marlin/src/config/examples/BIBO/TouchX/default/Configuration_adv.h
index a5afef4c16..5ccefe6428 100644
--- a/Marlin/src/config/examples/BIBO/TouchX/default/Configuration_adv.h
+++ b/Marlin/src/config/examples/BIBO/TouchX/default/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 2     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/BQ/Hephestos/Configuration_adv.h b/Marlin/src/config/examples/BQ/Hephestos/Configuration_adv.h
index f4618d4c50..2860799641 100644
--- a/Marlin/src/config/examples/BQ/Hephestos/Configuration_adv.h
+++ b/Marlin/src/config/examples/BQ/Hephestos/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/BQ/Hephestos_2/Configuration_adv.h b/Marlin/src/config/examples/BQ/Hephestos_2/Configuration_adv.h
index 1cfaebfb93..21115f65d2 100644
--- a/Marlin/src/config/examples/BQ/Hephestos_2/Configuration_adv.h
+++ b/Marlin/src/config/examples/BQ/Hephestos_2/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/BQ/WITBOX/Configuration_adv.h b/Marlin/src/config/examples/BQ/WITBOX/Configuration_adv.h
index f4618d4c50..2860799641 100644
--- a/Marlin/src/config/examples/BQ/WITBOX/Configuration_adv.h
+++ b/Marlin/src/config/examples/BQ/WITBOX/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Cartesio/Configuration_adv.h b/Marlin/src/config/examples/Cartesio/Configuration_adv.h
index 11ba9a9b62..a4e124f3f3 100644
--- a/Marlin/src/config/examples/Cartesio/Configuration_adv.h
+++ b/Marlin/src/config/examples/Cartesio/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Creality/CR-10/Configuration_adv.h b/Marlin/src/config/examples/Creality/CR-10/Configuration_adv.h
index ca0af674bb..8d157eab9a 100644
--- a/Marlin/src/config/examples/Creality/CR-10/Configuration_adv.h
+++ b/Marlin/src/config/examples/Creality/CR-10/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Creality/CR-10S/Configuration_adv.h b/Marlin/src/config/examples/Creality/CR-10S/Configuration_adv.h
index 51a8d27941..6abb4b4b22 100644
--- a/Marlin/src/config/examples/Creality/CR-10S/Configuration_adv.h
+++ b/Marlin/src/config/examples/Creality/CR-10S/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Creality/CR-10mini/Configuration_adv.h b/Marlin/src/config/examples/Creality/CR-10mini/Configuration_adv.h
index b18d14789a..886fbc8ac0 100644
--- a/Marlin/src/config/examples/Creality/CR-10mini/Configuration_adv.h
+++ b/Marlin/src/config/examples/Creality/CR-10mini/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Creality/CR-8/Configuration_adv.h b/Marlin/src/config/examples/Creality/CR-8/Configuration_adv.h
index 557dde89ac..a118d09b3a 100644
--- a/Marlin/src/config/examples/Creality/CR-8/Configuration_adv.h
+++ b/Marlin/src/config/examples/Creality/CR-8/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Creality/Ender-2/Configuration_adv.h b/Marlin/src/config/examples/Creality/Ender-2/Configuration_adv.h
index 8405e547c0..99ae40bdca 100644
--- a/Marlin/src/config/examples/Creality/Ender-2/Configuration_adv.h
+++ b/Marlin/src/config/examples/Creality/Ender-2/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Creality/Ender-3/Configuration_adv.h b/Marlin/src/config/examples/Creality/Ender-3/Configuration_adv.h
index aa53d51812..54a57e81dd 100644
--- a/Marlin/src/config/examples/Creality/Ender-3/Configuration_adv.h
+++ b/Marlin/src/config/examples/Creality/Ender-3/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Creality/Ender-4/Configuration_adv.h b/Marlin/src/config/examples/Creality/Ender-4/Configuration_adv.h
index 3876a9c559..2dd5c9f65a 100644
--- a/Marlin/src/config/examples/Creality/Ender-4/Configuration_adv.h
+++ b/Marlin/src/config/examples/Creality/Ender-4/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Einstart-S/Configuration_adv.h b/Marlin/src/config/examples/Einstart-S/Configuration_adv.h
index 698765a1ca..e890b89328 100644
--- a/Marlin/src/config/examples/Einstart-S/Configuration_adv.h
+++ b/Marlin/src/config/examples/Einstart-S/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Felix/Configuration_adv.h b/Marlin/src/config/examples/Felix/Configuration_adv.h
index 317324c6f3..8a954e9324 100644
--- a/Marlin/src/config/examples/Felix/Configuration_adv.h
+++ b/Marlin/src/config/examples/Felix/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/FlashForge/CreatorPro/Configuration_adv.h b/Marlin/src/config/examples/FlashForge/CreatorPro/Configuration_adv.h
index d06005ae41..4e1461581c 100644
--- a/Marlin/src/config/examples/FlashForge/CreatorPro/Configuration_adv.h
+++ b/Marlin/src/config/examples/FlashForge/CreatorPro/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/FolgerTech/i3-2020/Configuration_adv.h b/Marlin/src/config/examples/FolgerTech/i3-2020/Configuration_adv.h
index a8daafccc4..6cef2e73c8 100644
--- a/Marlin/src/config/examples/FolgerTech/i3-2020/Configuration_adv.h
+++ b/Marlin/src/config/examples/FolgerTech/i3-2020/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 2     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Formbot/Raptor/Configuration_adv.h b/Marlin/src/config/examples/Formbot/Raptor/Configuration_adv.h
index 7eb68c1412..4335cead86 100644
--- a/Marlin/src/config/examples/Formbot/Raptor/Configuration_adv.h
+++ b/Marlin/src/config/examples/Formbot/Raptor/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 2     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Formbot/T_Rex_2+/Configuration_adv.h b/Marlin/src/config/examples/Formbot/T_Rex_2+/Configuration_adv.h
index cb36de30f7..9961329dfc 100644
--- a/Marlin/src/config/examples/Formbot/T_Rex_2+/Configuration_adv.h
+++ b/Marlin/src/config/examples/Formbot/T_Rex_2+/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 10    // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Formbot/T_Rex_3/Configuration_adv.h b/Marlin/src/config/examples/Formbot/T_Rex_3/Configuration_adv.h
index 19f559137d..427c41df14 100644
--- a/Marlin/src/config/examples/Formbot/T_Rex_3/Configuration_adv.h
+++ b/Marlin/src/config/examples/Formbot/T_Rex_3/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 10    // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Geeetech/MeCreator2/Configuration_adv.h b/Marlin/src/config/examples/Geeetech/MeCreator2/Configuration_adv.h
index 6d93fd0d2e..4e9235b0ca 100644
--- a/Marlin/src/config/examples/Geeetech/MeCreator2/Configuration_adv.h
+++ b/Marlin/src/config/examples/Geeetech/MeCreator2/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Geeetech/Prusa i3 Pro C/Configuration_adv.h b/Marlin/src/config/examples/Geeetech/Prusa i3 Pro C/Configuration_adv.h
index 3fb163f520..4f2cc5f567 100644
--- a/Marlin/src/config/examples/Geeetech/Prusa i3 Pro C/Configuration_adv.h	
+++ b/Marlin/src/config/examples/Geeetech/Prusa i3 Pro C/Configuration_adv.h	
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Geeetech/Prusa i3 Pro W/Configuration_adv.h b/Marlin/src/config/examples/Geeetech/Prusa i3 Pro W/Configuration_adv.h
index 3fb163f520..4f2cc5f567 100644
--- a/Marlin/src/config/examples/Geeetech/Prusa i3 Pro W/Configuration_adv.h	
+++ b/Marlin/src/config/examples/Geeetech/Prusa i3 Pro W/Configuration_adv.h	
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Infitary/i3-M508/Configuration_adv.h b/Marlin/src/config/examples/Infitary/i3-M508/Configuration_adv.h
index 73bdf62dd1..e1f7984fef 100644
--- a/Marlin/src/config/examples/Infitary/i3-M508/Configuration_adv.h
+++ b/Marlin/src/config/examples/Infitary/i3-M508/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/JGAurora/A5/Configuration_adv.h b/Marlin/src/config/examples/JGAurora/A5/Configuration_adv.h
index 4bc3c5166d..149912837e 100644
--- a/Marlin/src/config/examples/JGAurora/A5/Configuration_adv.h
+++ b/Marlin/src/config/examples/JGAurora/A5/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/MakerParts/Configuration_adv.h b/Marlin/src/config/examples/MakerParts/Configuration_adv.h
index 9a977efdda..bd01a83732 100644
--- a/Marlin/src/config/examples/MakerParts/Configuration_adv.h
+++ b/Marlin/src/config/examples/MakerParts/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Malyan/M150/Configuration_adv.h b/Marlin/src/config/examples/Malyan/M150/Configuration_adv.h
index 85f736061c..c976f5d77a 100644
--- a/Marlin/src/config/examples/Malyan/M150/Configuration_adv.h
+++ b/Marlin/src/config/examples/Malyan/M150/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Malyan/M200/Configuration_adv.h b/Marlin/src/config/examples/Malyan/M200/Configuration_adv.h
index 2f65e8d30e..3f03df0f35 100644
--- a/Marlin/src/config/examples/Malyan/M200/Configuration_adv.h
+++ b/Marlin/src/config/examples/Malyan/M200/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Micromake/C1/enhanced/Configuration_adv.h b/Marlin/src/config/examples/Micromake/C1/enhanced/Configuration_adv.h
index 84e3a71615..d6781ad60f 100644
--- a/Marlin/src/config/examples/Micromake/C1/enhanced/Configuration_adv.h
+++ b/Marlin/src/config/examples/Micromake/C1/enhanced/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Mks/Robin/Configuration_adv.h b/Marlin/src/config/examples/Mks/Robin/Configuration_adv.h
index 70ec34d6db..bc9f6149b3 100644
--- a/Marlin/src/config/examples/Mks/Robin/Configuration_adv.h
+++ b/Marlin/src/config/examples/Mks/Robin/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Mks/Sbase/Configuration_adv.h b/Marlin/src/config/examples/Mks/Sbase/Configuration_adv.h
index 92227eca99..ab97398f05 100644
--- a/Marlin/src/config/examples/Mks/Sbase/Configuration_adv.h
+++ b/Marlin/src/config/examples/Mks/Sbase/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 6     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/RapideLite/RL200/Configuration_adv.h b/Marlin/src/config/examples/RapideLite/RL200/Configuration_adv.h
index c75fbefe45..1c30a37191 100644
--- a/Marlin/src/config/examples/RapideLite/RL200/Configuration_adv.h
+++ b/Marlin/src/config/examples/RapideLite/RL200/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/RigidBot/Configuration_adv.h b/Marlin/src/config/examples/RigidBot/Configuration_adv.h
index a11e33efc9..cf8abe0d65 100644
--- a/Marlin/src/config/examples/RigidBot/Configuration_adv.h
+++ b/Marlin/src/config/examples/RigidBot/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/SCARA/Configuration_adv.h b/Marlin/src/config/examples/SCARA/Configuration_adv.h
index 515dc02e97..dd760ba6f3 100644
--- a/Marlin/src/config/examples/SCARA/Configuration_adv.h
+++ b/Marlin/src/config/examples/SCARA/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Sanguinololu/Configuration_adv.h b/Marlin/src/config/examples/Sanguinololu/Configuration_adv.h
index 91843aacf3..820c2b41c8 100644
--- a/Marlin/src/config/examples/Sanguinololu/Configuration_adv.h
+++ b/Marlin/src/config/examples/Sanguinololu/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/TheBorg/Configuration_adv.h b/Marlin/src/config/examples/TheBorg/Configuration_adv.h
index 08f5dd90d1..128dd57882 100644
--- a/Marlin/src/config/examples/TheBorg/Configuration_adv.h
+++ b/Marlin/src/config/examples/TheBorg/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 6     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/TinyBoy2/Configuration_adv.h b/Marlin/src/config/examples/TinyBoy2/Configuration_adv.h
index a1db5bcc9c..faea40427c 100644
--- a/Marlin/src/config/examples/TinyBoy2/Configuration_adv.h
+++ b/Marlin/src/config/examples/TinyBoy2/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Tronxy/X3A/Configuration_adv.h b/Marlin/src/config/examples/Tronxy/X3A/Configuration_adv.h
index 50f7ca0902..ae9d30b456 100644
--- a/Marlin/src/config/examples/Tronxy/X3A/Configuration_adv.h
+++ b/Marlin/src/config/examples/Tronxy/X3A/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/UltiMachine/Archim1/Configuration_adv.h b/Marlin/src/config/examples/UltiMachine/Archim1/Configuration_adv.h
index d74bc59ac1..1b4376b50d 100644
--- a/Marlin/src/config/examples/UltiMachine/Archim1/Configuration_adv.h
+++ b/Marlin/src/config/examples/UltiMachine/Archim1/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/UltiMachine/Archim2/Configuration_adv.h b/Marlin/src/config/examples/UltiMachine/Archim2/Configuration_adv.h
index 06698fbf2c..4452a21f2e 100644
--- a/Marlin/src/config/examples/UltiMachine/Archim2/Configuration_adv.h
+++ b/Marlin/src/config/examples/UltiMachine/Archim2/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/VORONDesign/Configuration_adv.h b/Marlin/src/config/examples/VORONDesign/Configuration_adv.h
index 84bbd62cc6..e4d81a8505 100644
--- a/Marlin/src/config/examples/VORONDesign/Configuration_adv.h
+++ b/Marlin/src/config/examples/VORONDesign/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Velleman/K8200/Configuration_adv.h b/Marlin/src/config/examples/Velleman/K8200/Configuration_adv.h
index 80f0cce15b..58b9488960 100644
--- a/Marlin/src/config/examples/Velleman/K8200/Configuration_adv.h
+++ b/Marlin/src/config/examples/Velleman/K8200/Configuration_adv.h
@@ -88,6 +88,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 8     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Velleman/K8400/Configuration_adv.h b/Marlin/src/config/examples/Velleman/K8400/Configuration_adv.h
index 29b3401770..accc782278 100644
--- a/Marlin/src/config/examples/Velleman/K8400/Configuration_adv.h
+++ b/Marlin/src/config/examples/Velleman/K8400/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/WASP/PowerWASP/Configuration_adv.h b/Marlin/src/config/examples/WASP/PowerWASP/Configuration_adv.h
index 9763bfc32e..35d0a95a01 100644
--- a/Marlin/src/config/examples/WASP/PowerWASP/Configuration_adv.h
+++ b/Marlin/src/config/examples/WASP/PowerWASP/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/Wanhao/Duplicator 6/Configuration_adv.h b/Marlin/src/config/examples/Wanhao/Duplicator 6/Configuration_adv.h
index 97378fcdfa..529ebb59fd 100644
--- a/Marlin/src/config/examples/Wanhao/Duplicator 6/Configuration_adv.h	
+++ b/Marlin/src/config/examples/Wanhao/Duplicator 6/Configuration_adv.h	
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/delta/Anycubic/Kossel/Configuration_adv.h b/Marlin/src/config/examples/delta/Anycubic/Kossel/Configuration_adv.h
index 92e3209032..d06363b7e0 100644
--- a/Marlin/src/config/examples/delta/Anycubic/Kossel/Configuration_adv.h
+++ b/Marlin/src/config/examples/delta/Anycubic/Kossel/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/delta/FLSUN/auto_calibrate/Configuration_adv.h b/Marlin/src/config/examples/delta/FLSUN/auto_calibrate/Configuration_adv.h
index 9eb442c047..90ed68c9bc 100644
--- a/Marlin/src/config/examples/delta/FLSUN/auto_calibrate/Configuration_adv.h
+++ b/Marlin/src/config/examples/delta/FLSUN/auto_calibrate/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/delta/FLSUN/kossel/Configuration_adv.h b/Marlin/src/config/examples/delta/FLSUN/kossel/Configuration_adv.h
index 9eb442c047..90ed68c9bc 100644
--- a/Marlin/src/config/examples/delta/FLSUN/kossel/Configuration_adv.h
+++ b/Marlin/src/config/examples/delta/FLSUN/kossel/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/delta/FLSUN/kossel_mini/Configuration_adv.h b/Marlin/src/config/examples/delta/FLSUN/kossel_mini/Configuration_adv.h
index 3c5359e20b..361ec5d92b 100644
--- a/Marlin/src/config/examples/delta/FLSUN/kossel_mini/Configuration_adv.h
+++ b/Marlin/src/config/examples/delta/FLSUN/kossel_mini/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/delta/Geeetech/Rostock 301/Configuration_adv.h b/Marlin/src/config/examples/delta/Geeetech/Rostock 301/Configuration_adv.h
index 2df5dd8bf9..e864d53085 100644
--- a/Marlin/src/config/examples/delta/Geeetech/Rostock 301/Configuration_adv.h	
+++ b/Marlin/src/config/examples/delta/Geeetech/Rostock 301/Configuration_adv.h	
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/delta/MKS/SBASE/Configuration_adv.h b/Marlin/src/config/examples/delta/MKS/SBASE/Configuration_adv.h
index d61a32e816..e5620681ee 100644
--- a/Marlin/src/config/examples/delta/MKS/SBASE/Configuration_adv.h
+++ b/Marlin/src/config/examples/delta/MKS/SBASE/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 6     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/delta/Tevo Little Monster/Configuration_adv.h b/Marlin/src/config/examples/delta/Tevo Little Monster/Configuration_adv.h
index 08cec58140..c793d4df68 100644
--- a/Marlin/src/config/examples/delta/Tevo Little Monster/Configuration_adv.h	
+++ b/Marlin/src/config/examples/delta/Tevo Little Monster/Configuration_adv.h	
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 10     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/delta/generic/Configuration_adv.h b/Marlin/src/config/examples/delta/generic/Configuration_adv.h
index 3c5359e20b..361ec5d92b 100644
--- a/Marlin/src/config/examples/delta/generic/Configuration_adv.h
+++ b/Marlin/src/config/examples/delta/generic/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/delta/kossel_mini/Configuration_adv.h b/Marlin/src/config/examples/delta/kossel_mini/Configuration_adv.h
index 3c5359e20b..361ec5d92b 100644
--- a/Marlin/src/config/examples/delta/kossel_mini/Configuration_adv.h
+++ b/Marlin/src/config/examples/delta/kossel_mini/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/delta/kossel_xl/Configuration_adv.h b/Marlin/src/config/examples/delta/kossel_xl/Configuration_adv.h
index 702c319b49..174433816c 100644
--- a/Marlin/src/config/examples/delta/kossel_xl/Configuration_adv.h
+++ b/Marlin/src/config/examples/delta/kossel_xl/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/gCreate/gMax1.5+/Configuration_adv.h b/Marlin/src/config/examples/gCreate/gMax1.5+/Configuration_adv.h
index 1785ce62bc..f4b074f3c3 100644
--- a/Marlin/src/config/examples/gCreate/gMax1.5+/Configuration_adv.h
+++ b/Marlin/src/config/examples/gCreate/gMax1.5+/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 3     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/makibox/Configuration_adv.h b/Marlin/src/config/examples/makibox/Configuration_adv.h
index 6b9f4512b0..a697d85771 100644
--- a/Marlin/src/config/examples/makibox/Configuration_adv.h
+++ b/Marlin/src/config/examples/makibox/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/tvrrug/Round2/Configuration_adv.h b/Marlin/src/config/examples/tvrrug/Round2/Configuration_adv.h
index 7e5e37caff..5af50c00c9 100644
--- a/Marlin/src/config/examples/tvrrug/Round2/Configuration_adv.h
+++ b/Marlin/src/config/examples/tvrrug/Round2/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/config/examples/wt150/Configuration_adv.h b/Marlin/src/config/examples/wt150/Configuration_adv.h
index a82743befd..5a6e470b14 100644
--- a/Marlin/src/config/examples/wt150/Configuration_adv.h
+++ b/Marlin/src/config/examples/wt150/Configuration_adv.h
@@ -78,6 +78,9 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && ENABLED(PIDTEMP)
+    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #endif
 
   /**
    * Whenever an M104, M109, or M303 increases the target temperature, the
diff --git a/Marlin/src/inc/Conditionals_post.h b/Marlin/src/inc/Conditionals_post.h
index f50a0ffdc7..4b22ca4657 100644
--- a/Marlin/src/inc/Conditionals_post.h
+++ b/Marlin/src/inc/Conditionals_post.h
@@ -1260,11 +1260,14 @@
 #endif
 
 /**
- * Heater & Fan Pausing
+ * Heater, Fan, and Probe interactions
  */
 #if FAN_COUNT == 0
   #undef PROBING_FANS_OFF
+  #undef ADAPTIVE_FAN_SLOWING
+  #undef NO_FAN_SLOWING_IN_PID_TUNING
 #endif
+
 #define QUIET_PROBING (HAS_BED_PROBE && (ENABLED(PROBING_HEATERS_OFF) || ENABLED(PROBING_FANS_OFF) || DELAY_BEFORE_PROBING > 0))
 #define HEATER_IDLE_HANDLER (ENABLED(ADVANCED_PAUSE_FEATURE) || ENABLED(PROBING_HEATERS_OFF))
 
diff --git a/Marlin/src/module/temperature.cpp b/Marlin/src/module/temperature.cpp
index 0cb8b04349..a201fee31b 100644
--- a/Marlin/src/module/temperature.cpp
+++ b/Marlin/src/module/temperature.cpp
@@ -96,6 +96,10 @@ Temperature thermalManager;
 
 // public:
 
+#if ENABLED(NO_FAN_SLOWING_IN_PID_TUNING)
+  bool Temperature::adaptive_fan_slowing = true;
+#endif
+
 float Temperature::current_temperature[HOTENDS]; // = { 0.0 };
 int16_t Temperature::current_temperature_raw[HOTENDS], // = { 0 }
         Temperature::target_temperature[HOTENDS]; // = { 0 }
@@ -392,6 +396,10 @@ uint8_t Temperature::soft_pwm_amount[HOTENDS];
       LEDColor color = ONHEATINGSTART();
     #endif
 
+    #if ENABLED(NO_FAN_SLOWING_IN_PID_TUNING)
+      adaptive_fan_slowing = false;
+    #endif
+
     // PID Tuning loop
     while (wait_for_heatup) {
 
@@ -570,18 +578,27 @@ uint8_t Temperature::soft_pwm_amount[HOTENDS];
             _SET_BED_PID();
           #endif
         }
+
         #if ENABLED(PRINTER_EVENT_LEDS)
           printerEventLEDs.onPidTuningDone(color);
         #endif
 
-        return;
+        goto EXIT_M303;
       }
       ui.update();
     }
+
     disable_all_heaters();
+
     #if ENABLED(PRINTER_EVENT_LEDS)
       printerEventLEDs.onPidTuningDone(color);
     #endif
+
+    EXIT_M303:
+      #if ENABLED(NO_FAN_SLOWING_IN_PID_TUNING)
+        adaptive_fan_slowing = true;
+      #endif
+      return;
   }
 
 #endif // HAS_PID_HEATING
@@ -1627,8 +1644,8 @@ void Temperature::init() {
       // While the temperature is stable watch for a bad temperature
       case TRStable:
 
-        #if ENABLED(ADAPTIVE_FAN_SLOWING) && FAN_COUNT > 0
-          if (heater_id >= 0) {
+        #if ENABLED(ADAPTIVE_FAN_SLOWING)
+          if (adaptive_fan_slowing && heater_id >= 0) {
             const int fan_index = MIN(heater_id, FAN_COUNT - 1);
             if (fan_speed[fan_index] == 0 || current >= tr_target_temperature[heater_id] - (hysteresis_degc * 0.25f))
               fan_speed_scaler[fan_index] = 128;
diff --git a/Marlin/src/module/temperature.h b/Marlin/src/module/temperature.h
index 0d67163cad..d68ce819e6 100644
--- a/Marlin/src/module/temperature.h
+++ b/Marlin/src/module/temperature.h
@@ -565,6 +565,12 @@ class Temperature {
     #if HAS_PID_HEATING
       static void PID_autotune(const float &target, const int8_t hotend, const int8_t ncycles, const bool set_result=false);
 
+      #if ENABLED(NO_FAN_SLOWING_IN_PID_TUNING)
+        static bool adaptive_fan_slowing;
+      #elif ENABLED(ADAPTIVE_FAN_SLOWING)
+        constexpr static bool adaptive_fan_slowing = true;
+      #endif
+
       /**
        * Update the temp manager when PID values change
        */
diff --git a/buildroot/share/tests/LPC1768_tests b/buildroot/share/tests/LPC1768_tests
index f79cefa00c..56e405e7d7 100755
--- a/buildroot/share/tests/LPC1768_tests
+++ b/buildroot/share/tests/LPC1768_tests
@@ -36,7 +36,7 @@ opt_set EXTRUDERS 2
 opt_set TEMP_SENSOR_0 1
 opt_set TEMP_SENSOR_1 5
 opt_set TEMP_SENSOR_BED 1
-opt_enable REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER SDSUPPORT ADAPTIVE_FAN_SLOWING \
+opt_enable REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER SDSUPPORT ADAPTIVE_FAN_SLOWING NO_FAN_SLOWING_IN_PID_TUNING \
            FILAMENT_WIDTH_SENSOR FILAMENT_LCD_DISPLAY \
            FIX_MOUNTED_PROBE Z_SAFE_HOMING AUTO_BED_LEVELING_BILINEAR Z_MIN_PROBE_REPEATABILITY_TEST DEBUG_LEVELING_FEATURE \
            BABYSTEPPING BABYSTEP_XY BABYSTEP_ZPROBE_OFFSET BABYSTEP_ZPROBE_GFX_OVERLAY \