diff --git a/Marlin/src/gcode/parser.cpp b/Marlin/src/gcode/parser.cpp
index 611dd3e744..2dcd521bec 100644
--- a/Marlin/src/gcode/parser.cpp
+++ b/Marlin/src/gcode/parser.cpp
@@ -60,7 +60,7 @@ int GCodeParser::codenum;
 
 #if ENABLED(FASTER_GCODE_PARSER)
   // Optimized Parameters
-  byte GCodeParser::codebits[4];   // found bits
+  uint32_t GCodeParser::codebits;  // found bits
   uint8_t GCodeParser::param[26];  // parameter offsets from command_ptr
 #else
   char *GCodeParser::command_args; // start of parameters
@@ -83,7 +83,7 @@ void GCodeParser::reset() {
     subcode = 0;                        // No command sub-code
   #endif
   #if ENABLED(FASTER_GCODE_PARSER)
-    ZERO(codebits);                     // No codes yet
+    codebits = 0;                       // No codes yet
     //ZERO(param);                      // No parameters (should be safe to comment out this line)
   #endif
 }
diff --git a/Marlin/src/gcode/parser.h b/Marlin/src/gcode/parser.h
index 0d33462904..62fd4cd7cf 100644
--- a/Marlin/src/gcode/parser.h
+++ b/Marlin/src/gcode/parser.h
@@ -51,7 +51,7 @@ private:
   static char *value_ptr;           // Set by seen, used to fetch the value
 
   #if ENABLED(FASTER_GCODE_PARSER)
-    static byte codebits[4];        // Parameters pre-scanned
+    static uint32_t codebits;       // Parameters pre-scanned
     static uint8_t param[26];       // For A-Z, offsets into command args
   #else
     static char *command_args;      // Args start here, for slow scan
@@ -88,26 +88,22 @@ public:
   // Reset is done before parsing
   static void reset();
 
-  // Index so that 'X' falls on index 24
-  #define PARAM_IND(N)  ((N) >> 3)
-  #define PARAM_BIT(N)  ((N) & 0x7)
-  #define LETTER_OFF(N) ((N) - 'A')
-  #define LETTER_IND(N) PARAM_IND(LETTER_OFF(N))
-  #define LETTER_BIT(N) PARAM_BIT(LETTER_OFF(N))
+  #define LETTER_BIT(N) ((N) - 'A')
 
   #if ENABLED(FASTER_GCODE_PARSER)
 
     // Set the flag and pointer for a parameter
     static void set(const char c, char * const ptr) {
-      const uint8_t ind = LETTER_OFF(c);
+      const uint8_t ind = LETTER_BIT(c);
       if (ind >= COUNT(param)) return;           // Only A-Z
-      SBI(codebits[PARAM_IND(ind)], PARAM_BIT(ind));        // parameter exists
+      SBI(codebits, ind);                        // parameter exists
       param[ind] = ptr ? ptr - command_ptr : 0;  // parameter offset or 0
       #if ENABLED(DEBUG_GCODE_PARSER)
         if (codenum == 800) {
-          SERIAL_ECHOPAIR("Set bit ", (int)PARAM_BIT(ind));
-          SERIAL_ECHOPAIR(" of index ", (int)PARAM_IND(ind));
-          SERIAL_ECHOLNPAIR(" | param = ", (int)param[ind]);
+          SERIAL_ECHOPAIR("Set bit ", (int)ind);
+          SERIAL_ECHOPAIR(" of codebits (", hex_address((void*)(codebits >> 16)));
+          print_hex_word((uint16_t)(codebits & 0xFFFF));
+          SERIAL_ECHOLNPAIR(") | param = ", (int)param[ind]);
         }
       #endif
     }
@@ -115,16 +111,19 @@ public:
     // Code seen bit was set. If not found, value_ptr is unchanged.
     // This allows "if (seen('A')||seen('B'))" to use the last-found value.
     static bool seen(const char c) {
-      const uint8_t ind = LETTER_OFF(c);
+      const uint8_t ind = LETTER_BIT(c);
       if (ind >= COUNT(param)) return false; // Only A-Z
-      const bool b = TEST(codebits[PARAM_IND(ind)], PARAM_BIT(ind));
-      if (b) value_ptr = param[ind] ? command_ptr + param[ind] : (char*)NULL;
+      const bool b = TEST(codebits, ind);
+      if (b) {
+        char * const ptr = command_ptr + param[ind];
+        value_ptr = param[ind] && valid_float(ptr) ? ptr : (char*)NULL;
+      }
       return b;
     }
 
-    static bool seen_any() { return codebits[3] || codebits[2] || codebits[1] || codebits[0]; }
+    static bool seen_any() { return !!codebits; }
 
-    #define SEEN_TEST(L) TEST(codebits[LETTER_IND(L)], LETTER_BIT(L))
+    #define SEEN_TEST(L) TEST(codebits, LETTER_BIT(L))
 
   #else // !FASTER_GCODE_PARSER