diff --git a/Marlin/src/HAL/HAL_STM32F1/HAL.cpp b/Marlin/src/HAL/HAL_STM32F1/HAL.cpp
index 69ac127a4e..0a58c45d1f 100644
--- a/Marlin/src/HAL/HAL_STM32F1/HAL.cpp
+++ b/Marlin/src/HAL/HAL_STM32F1/HAL.cpp
@@ -260,7 +260,11 @@ extern "C" {
 void HAL_adc_init(void) {
   // configure the ADC
   adc.calibrate();
-  adc.setSampleRate(ADC_SMPR_41_5); // ?
+  #if F_CPU > 72000000
+    adc.setSampleRate(ADC_SMPR_71_5); // 71.5 ADC cycles
+  #else
+    adc.setSampleRate(ADC_SMPR_41_5); // 41.5 ADC cycles
+  #endif
   adc.setPins(adc_pins, ADC_PIN_COUNT);
   adc.setDMA(HAL_adc_results, (uint16_t)ADC_PIN_COUNT, (uint32_t)(DMA_MINC_MODE | DMA_CIRC_MODE), nullptr);
   adc.setScanMode();
diff --git a/Marlin/src/HAL/HAL_STM32F1/HAL_spi_STM32F1.cpp b/Marlin/src/HAL/HAL_STM32F1/HAL_spi_STM32F1.cpp
index 21979c1052..a0fdf6b65b 100644
--- a/Marlin/src/HAL/HAL_STM32F1/HAL_spi_STM32F1.cpp
+++ b/Marlin/src/HAL/HAL_STM32F1/HAL_spi_STM32F1.cpp
@@ -104,7 +104,7 @@ void spiInit(uint8_t spiRate) {
  * @details
  */
 uint8_t spiRec(void) {
-  uint8_t returnByte = SPI.transfer(0xFF);
+  uint8_t returnByte = SPI.transfer(ff);
   return returnByte;
 }
 
diff --git a/Marlin/src/HAL/HAL_STM32F1/STM32F1_flag_script.py b/Marlin/src/HAL/HAL_STM32F1/STM32F1_flag_script.py
index 5bb2f18fb6..6310740fe0 100644
--- a/Marlin/src/HAL/HAL_STM32F1/STM32F1_flag_script.py
+++ b/Marlin/src/HAL/HAL_STM32F1/STM32F1_flag_script.py
@@ -4,7 +4,6 @@ import sys
 #dynamic build flags for generic compile options
 if __name__ == "__main__":
   args = " ".join([ "-std=gnu11",
-                    "-std=gnu++11",
                     "-Os",
                     "-mcpu=cortex-m3",
                     "-mthumb",
diff --git a/Marlin/src/lcd/dogm/HAL_LCD_com_defines.h b/Marlin/src/lcd/dogm/HAL_LCD_com_defines.h
index a320d759cf..efd326c2b7 100644
--- a/Marlin/src/lcd/dogm/HAL_LCD_com_defines.h
+++ b/Marlin/src/lcd/dogm/HAL_LCD_com_defines.h
@@ -25,7 +25,6 @@
 
 #ifndef U8G_HAL_LINKS
 
-
   #ifdef __SAM3X8E__
     uint8_t u8g_com_HAL_DUE_sw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
     #define U8G_COM_HAL_SW_SPI_FN  u8g_com_HAL_DUE_sw_spi_fn
@@ -33,44 +32,41 @@
     #define U8G_COM_HAL_HW_SPI_FN u8g_com_HAL_DUE_shared_hw_spi_fn
     uint8_t u8g_com_HAL_DUE_ST7920_sw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
     #define U8G_COM_ST7920_HAL_SW_SPI u8g_com_HAL_DUE_ST7920_sw_spi_fn
+    #define U8G_COM_ST7920_HAL_HW_SPI u8g_com_arduino_st7920_hw_spi_fn
   #elif defined(__STM32F1__)
     uint8_t u8g_com_HAL_STM32F1_sw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
     #define U8G_COM_HAL_SW_SPI_FN u8g_com_HAL_STM32F1_sw_spi_fn
-    uint8_t u8g_com_arduino_hw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
-    //#define U8G_COM_HAL_HW_SPI_FN u8g_com_arduino_hw_spi_fn
     #define U8G_COM_HAL_HW_SPI_FN u8g_com_stm32duino_hw_spi_fn
-    uint8_t u8g_com_arduino_st7920_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
-    //#define U8G_COM_ST7920_HAL_SW_SPI u8g_com_arduino_st7920_spi_fn
     #define U8G_COM_ST7920_HAL_SW_SPI u8g_com_std_sw_spi_fn
     #define U8G_COM_ST7920_HAL_HW_SPI u8g_com_stm32duino_hw_spi_fn
   #elif defined(ARDUINO_ARCH_STM32)
-    uint8_t u8g_com_arduino_std_sw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
     #define U8G_COM_HAL_SW_SPI_FN u8g_com_arduino_std_sw_spi_fn
-    uint8_t u8g_com_stm32duino_hw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
     #define U8G_COM_HAL_HW_SPI_FN u8g_com_stm32duino_hw_spi_fn
-    uint8_t u8g_com_arduino_st7920_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
     #define U8G_COM_ST7920_HAL_SW_SPI u8g_com_arduino_st7920_spi_fn
-  #else
+    #define U8G_COM_ST7920_HAL_HW_SPI u8g_com_stm32duino_hw_spi_fn
+  #elif defined(__AVR__)
     uint8_t u8g_com_HAL_AVR_sw_sp_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
-    #define U8G_COM_HAL_SW_SPI_FN  u8g_com_HAL_AVR_sw_sp_fn // AVR ?
-    uint8_t u8g_com_arduino_hw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
+    #define U8G_COM_HAL_SW_SPI_FN  u8g_com_HAL_AVR_sw_sp_fn
     #define U8G_COM_HAL_HW_SPI_FN u8g_com_arduino_hw_spi_fn
-    uint8_t u8g_com_arduino_st7920_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
     #define U8G_COM_ST7920_HAL_SW_SPI u8g_com_arduino_st7920_spi_fn
+    #define U8G_COM_ST7920_HAL_HW_SPI u8g_com_arduino_st7920_hw_spi_fn
+  #else
+    #define U8G_COM_HAL_SW_SPI_FN u8g_com_arduino_std_sw_spi_fn
+    #define U8G_COM_HAL_HW_SPI_FN u8g_com_arduino_hw_spi_fn
+    #define U8G_COM_ST7920_HAL_SW_SPI u8g_com_arduino_st7920_spi_fn
+    #define U8G_COM_ST7920_HAL_HW_SPI u8g_com_arduino_st7920_hw_spi_fn
   #endif
 
-  uint8_t u8g_com_arduino_st7920_hw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
-  #define U8G_COM_ST7920_HAL_HW_SPI u8g_com_arduino_st7920_hw_spi_fn
-
   uint8_t u8g_com_HAL_LPC1768_ssd_hw_i2c_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
   #define U8G_COM_SSD_I2C_HAL u8g_com_arduino_ssd_i2c_fn
 
-  #if defined(ARDUINO_ARCH_STM32F1) && PIN_EXISTS(FSMC_CS)
+  #if PIN_EXISTS(FSMC_CS)
     uint8_t u8g_com_stm32duino_fsmc_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
     #define U8G_COM_HAL_FSMC_FN u8g_com_stm32duino_fsmc_fn
   #else
     #define U8G_COM_HAL_FSMC_FN u8g_com_null_fn
   #endif
+
 #elif TARGET_LPC1768
   uint8_t u8g_com_HAL_LPC1768_sw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
   #define U8G_COM_HAL_SW_SPI_FN u8g_com_HAL_LPC1768_sw_spi_fn
diff --git a/Marlin/src/lcd/dogm/u8g_dev_tft_320x240_upscale_from_128x64.cpp b/Marlin/src/lcd/dogm/u8g_dev_tft_320x240_upscale_from_128x64.cpp
index 971bc4c2be..72ed6c34de 100644
--- a/Marlin/src/lcd/dogm/u8g_dev_tft_320x240_upscale_from_128x64.cpp
+++ b/Marlin/src/lcd/dogm/u8g_dev_tft_320x240_upscale_from_128x64.cpp
@@ -334,7 +334,6 @@ uint8_t u8g_dev_tft_320x240_upscale_from_128x64_fn(u8g_t *u8g, u8g_dev_t *dev, u
   #else
     uint16_t buffer[256]; // 16-bit RGB 565 pixel line buffer
   #endif
-  uint16_t i;
   switch (msg) {
     case U8G_DEV_MSG_INIT:
       dev->com_fn(u8g, U8G_COM_MSG_INIT, U8G_SPI_CLK_CYCLE_NONE, &lcd_id);
diff --git a/config/examples/Alfawise/U20/Configuration.h b/config/examples/Alfawise/U20/Configuration.h
index 671bb23b9a..5b62c0d844 100644
--- a/config/examples/Alfawise/U20/Configuration.h
+++ b/config/examples/Alfawise/U20/Configuration.h
@@ -1619,8 +1619,11 @@
   // Middle point of circle
   #define NOZZLE_CLEAN_CIRCLE_MIDDLE NOZZLE_CLEAN_START_POINT
 
-  // Moves the nozzle to the initial position
+  // Move the nozzle to the initial position after cleaning
   #define NOZZLE_CLEAN_GOBACK
+
+  // Enable for a purge/clean station that's always at the gantry height (thus no Z move)
+  //#define NOZZLE_CLEAN_NO_Z
 #endif
 
 /**
@@ -2123,7 +2126,7 @@
 #define MKS_ROBIN_TFT
 
 //=============================================================================
-//============================= SPI Touch Screens =============================
+//============================  Other Controllers  ============================
 //=============================================================================
 
 #define TOUCH_BUTTONS
@@ -2147,14 +2150,6 @@
   #endif
 #endif
 
-//=============================================================================
-//============================  Other Controllers  ============================
-//=============================================================================
-
-//
-// CONTROLLER TYPE: Keypad / Add-on
-//
-
 //
 // RepRapWorld REPRAPWORLD_KEYPAD v1.1
 // http://reprapworld.com/?products_details&products_id=202&cPath=1591_1626