diff --git a/Marlin/Configuration_adv.h b/Marlin/Configuration_adv.h
index 71f46bfe8a79..16f8bdee1adf 100644
--- a/Marlin/Configuration_adv.h
+++ b/Marlin/Configuration_adv.h
@@ -304,8 +304,8 @@
   #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
   //#define ADAPTIVE_FAN_SLOWING              // Slow part cooling fan if temperature drops
-  #if BOTH(ADAPTIVE_FAN_SLOWING, PIDTEMP)
-    //#define NO_FAN_SLOWING_IN_PID_TUNING    // Don't slow fan speed during M303
+  #if ENABLED(ADAPTIVE_FAN_SLOWING) && EITHER(MPCTEMP, PIDTEMP)
+    //#define TEMP_TUNING_MAINTAIN_FAN        // Don't slow fan speed during M303 or M306 T
   #endif
 
   /**
diff --git a/Marlin/src/inc/Conditionals_post.h b/Marlin/src/inc/Conditionals_post.h
index 5ec428edf29d..cf6c560b5cc7 100644
--- a/Marlin/src/inc/Conditionals_post.h
+++ b/Marlin/src/inc/Conditionals_post.h
@@ -3054,7 +3054,7 @@
  */
 #if !HAS_FAN
   #undef ADAPTIVE_FAN_SLOWING
-  #undef NO_FAN_SLOWING_IN_PID_TUNING
+  #undef TEMP_TUNING_MAINTAIN_FAN
 #endif
 #if !BOTH(HAS_BED_PROBE, HAS_FAN)
   #undef PROBING_FANS_OFF
diff --git a/Marlin/src/inc/SanityCheck.h b/Marlin/src/inc/SanityCheck.h
index b5a37307ab32..c501c328c769 100644
--- a/Marlin/src/inc/SanityCheck.h
+++ b/Marlin/src/inc/SanityCheck.h
@@ -97,6 +97,8 @@
   #error "Thermal Runaway Protection for hotends is now enabled with THERMAL_PROTECTION_HOTENDS."
 #elif DISABLED(THERMAL_PROTECTION_BED) && defined(THERMAL_PROTECTION_BED_PERIOD)
   #error "Thermal Runaway Protection for the bed is now enabled with THERMAL_PROTECTION_BED."
+#elif defined(NO_FAN_SLOWING_IN_PID_TUNING)
+  #error "NO_FAN_SLOWING_IN_PID_TUNING is now TEMP_TUNING_MAINTAIN_FAN."
 #elif (CORE_IS_XZ || CORE_IS_YZ) && ENABLED(Z_LATE_ENABLE)
   #error "Z_LATE_ENABLE can't be used with COREXZ, COREZX, COREYZ, or COREZY."
 #elif defined(X_HOME_RETRACT_MM)
diff --git a/Marlin/src/module/temperature.cpp b/Marlin/src/module/temperature.cpp
index 5d4ccc0a5189..d5508401dec0 100644
--- a/Marlin/src/module/temperature.cpp
+++ b/Marlin/src/module/temperature.cpp
@@ -311,7 +311,7 @@ PGMSTR(str_t_heating_failed, STR_T_HEATING_FAILED);
  * public:
  */
 
-#if ENABLED(NO_FAN_SLOWING_IN_PID_TUNING)
+#if ENABLED(TEMP_TUNING_MAINTAIN_FAN)
   bool Temperature::adaptive_fan_slowing = true;
 #endif
 
@@ -688,7 +688,7 @@ volatile bool Temperature::raw_temps_ready = false;
       LEDColor color = ONHEATINGSTART();
     #endif
 
-    TERN_(NO_FAN_SLOWING_IN_PID_TUNING, adaptive_fan_slowing = false);
+    TERN_(TEMP_TUNING_MAINTAIN_FAN, adaptive_fan_slowing = false);
 
     LCD_MESSAGE(MSG_HEATING);
 
@@ -876,7 +876,7 @@ volatile bool Temperature::raw_temps_ready = false;
     TERN_(DWIN_PID_TUNE, DWIN_PidTuning(PID_DONE));
 
     EXIT_M303:
-      TERN_(NO_FAN_SLOWING_IN_PID_TUNING, adaptive_fan_slowing = true);
+      TERN_(TEMP_TUNING_MAINTAIN_FAN, adaptive_fan_slowing = true);
       return;
   }
 
@@ -910,6 +910,7 @@ volatile bool Temperature::raw_temps_ready = false;
         return false;
       }
 
+      wait_for_heatup = false;
       return true;
     };
 
@@ -927,6 +928,8 @@ volatile bool Temperature::raw_temps_ready = false;
         #endif
 
         do_z_clearance(MPC_TUNING_END_Z);
+
+        TERN_(TEMP_TUNING_MAINTAIN_FAN, adaptive_fan_slowing = true);
       }
     } on_exit;
 
@@ -935,6 +938,8 @@ volatile bool Temperature::raw_temps_ready = false;
     MPCHeaterInfo &hotend = temp_hotend[active_extruder];
     MPC_t &mpc = hotend.mpc;
 
+    TERN_(TEMP_TUNING_MAINTAIN_FAN, adaptive_fan_slowing = false);
+
     // Move to center of bed, just above bed height and cool with max fan
     gcode.home_all_axes(true);
     disable_all_heaters();
@@ -970,7 +975,6 @@ volatile bool Temperature::raw_temps_ready = false;
         next_test_ms += 10000UL;
       }
     }
-    wait_for_heatup = false;
 
     #if HAS_FAN
       set_fan_speed(EITHER(MPC_FAN_0_ALL_HOTENDS, MPC_FAN_0_ACTIVE_HOTEND) ? 0 : active_extruder, 0);
@@ -989,6 +993,7 @@ volatile bool Temperature::raw_temps_ready = false;
     uint16_t sample_distance = 1;
     float t1_time = 0;
 
+    wait_for_heatup = true;
     for (;;) { // Can be interrupted with M108
       if (!housekeeping(ms, current_temp, next_report_ms)) return;
 
@@ -1045,6 +1050,7 @@ volatile bool Temperature::raw_temps_ready = false;
     #endif
     float last_temp = current_temp;
 
+    wait_for_heatup = true;
     for (;;) { // Can be interrupted with M108
       if (!housekeeping(ms, current_temp, next_report_ms)) return;
 
@@ -4124,6 +4130,7 @@ void Temperature::isr() {
 
       } while (wait_for_heatup && TEMP_CONDITIONS);
 
+      // If wait_for_heatup is set, temperature was reached, no cancel
       if (wait_for_heatup) {
         wait_for_heatup = false;
         #if HAS_DWIN_E3V2_BASIC
@@ -4262,6 +4269,7 @@ void Temperature::isr() {
 
       } while (wait_for_heatup && TEMP_BED_CONDITIONS);
 
+      // If wait_for_heatup is set, temperature was reached, no cancel
       if (wait_for_heatup) {
         wait_for_heatup = false;
         ui.reset_status();
@@ -4340,6 +4348,7 @@ void Temperature::isr() {
         }
       }
 
+      // If wait_for_heatup is set, temperature was reached, no cancel
       if (wait_for_heatup) {
         wait_for_heatup = false;
         ui.reset_status();
@@ -4439,6 +4448,7 @@ void Temperature::isr() {
         }
       } while (wait_for_heatup && TEMP_CHAMBER_CONDITIONS);
 
+      // If wait_for_heatup is set, temperature was reached, no cancel
       if (wait_for_heatup) {
         wait_for_heatup = false;
         ui.reset_status();
@@ -4525,6 +4535,7 @@ void Temperature::isr() {
           first_loop = false;
         #endif // TEMP_COOLER_RESIDENCY_TIME > 0
 
+        // Prevent a wait-forever situation if R is misused i.e. M191 R0
         if (wants_to_cool) {
           // Break after MIN_COOLING_SLOPE_TIME_CHAMBER seconds
           // if the temperature did not drop at least MIN_COOLING_SLOPE_DEG_CHAMBER
@@ -4537,7 +4548,7 @@ void Temperature::isr() {
 
       } while (wait_for_heatup && TEMP_COOLER_CONDITIONS);
 
-      // Prevent a wait-forever situation if R is misused i.e. M191 R0
+      // If wait_for_heatup is set, temperature was reached, no cancel
       if (wait_for_heatup) {
         wait_for_heatup = false;
         ui.reset_status();
diff --git a/Marlin/src/module/temperature.h b/Marlin/src/module/temperature.h
index 9ac5db44edfa..c947a6789abe 100644
--- a/Marlin/src/module/temperature.h
+++ b/Marlin/src/module/temperature.h
@@ -1173,7 +1173,7 @@ class Temperature {
 
       static void PID_autotune(const celsius_t target, const heater_id_t heater_id, const int8_t ncycles, const bool set_result=false);
 
-      #if ENABLED(NO_FAN_SLOWING_IN_PID_TUNING)
+      #if ENABLED(TEMP_TUNING_MAINTAIN_FAN)
         static bool adaptive_fan_slowing;
       #elif ENABLED(ADAPTIVE_FAN_SLOWING)
         static constexpr bool adaptive_fan_slowing = true;
diff --git a/buildroot/tests/LPC1768 b/buildroot/tests/LPC1768
index 535e776a3892..2e680b60d797 100755
--- a/buildroot/tests/LPC1768
+++ b/buildroot/tests/LPC1768
@@ -40,7 +40,7 @@ opt_set MOTHERBOARD BOARD_RAMPS_14_RE_ARM_EEB \
         NOZZLE_CLEAN_MIN_TEMP 170 \
         NOZZLE_CLEAN_START_POINT "{ {  10, 10, 3 }, {  10, 10, 3 } }" \
         NOZZLE_CLEAN_END_POINT "{ {  10, 20, 3 }, {  10, 20, 3 } }"
-opt_enable REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER ADAPTIVE_FAN_SLOWING NO_FAN_SLOWING_IN_PID_TUNING \
+opt_enable REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER ADAPTIVE_FAN_SLOWING TEMP_TUNING_MAINTAIN_FAN \
            FILAMENT_WIDTH_SENSOR FILAMENT_LCD_DISPLAY PID_EXTRUSION_SCALING SOUND_MENU_ITEM \
            NOZZLE_AS_PROBE AUTO_BED_LEVELING_BILINEAR PREHEAT_BEFORE_LEVELING G29_RETRY_AND_RECOVER Z_MIN_PROBE_REPEATABILITY_TEST DEBUG_LEVELING_FEATURE \
            ASSISTED_TRAMMING ASSISTED_TRAMMING_WIZARD REPORT_TRAMMING_MM ASSISTED_TRAMMING_WAIT_POSITION \
diff --git a/buildroot/tests/LPC1769 b/buildroot/tests/LPC1769
index 086dffffc92c..ec5c824450c6 100755
--- a/buildroot/tests/LPC1769
+++ b/buildroot/tests/LPC1769
@@ -18,7 +18,7 @@ opt_set MOTHERBOARD BOARD_SMOOTHIEBOARD \
         GRID_MAX_POINTS_X 16 \
         NOZZLE_CLEAN_START_POINT "{ {  10, 10, 3 }, {  10, 10, 3 } }" \
         NOZZLE_CLEAN_END_POINT "{ {  10, 20, 3 }, {  10, 20, 3 } }"
-opt_enable TFTGLCD_PANEL_SPI SDSUPPORT ADAPTIVE_FAN_SLOWING NO_FAN_SLOWING_IN_PID_TUNING \
+opt_enable TFTGLCD_PANEL_SPI SDSUPPORT ADAPTIVE_FAN_SLOWING TEMP_TUNING_MAINTAIN_FAN \
            MAX31865_SENSOR_OHMS_0 MAX31865_CALIBRATION_OHMS_0 \
            FIX_MOUNTED_PROBE AUTO_BED_LEVELING_BILINEAR G29_RETRY_AND_RECOVER Z_MIN_PROBE_REPEATABILITY_TEST DEBUG_LEVELING_FEATURE \
            BABYSTEPPING BABYSTEP_XY BABYSTEP_ZPROBE_OFFSET BED_TRAMMING_USE_PROBE BED_TRAMMING_VERIFY_RAISED \