diff --git a/Marlin/Configuration.h b/Marlin/Configuration.h
index 46bc9aeafac..08e495e96de 100644
--- a/Marlin/Configuration.h
+++ b/Marlin/Configuration.h
@@ -1002,6 +1002,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index 9fba4e1d2e8..64911ee9e88 100644
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -7302,7 +7302,9 @@ inline void gcode_M109() {
   wait_for_heatup = true;
   millis_t now, next_temp_ms = 0, next_cool_check_ms = 0;
 
-  KEEPALIVE_STATE(NOT_BUSY);
+  #if DISABLED(BUSY_WHILE_HEATING)
+    KEEPALIVE_STATE(NOT_BUSY);
+  #endif
 
   #if ENABLED(PRINTER_EVENT_LEDS)
     const float start_temp = thermalManager.degHotend(target_extruder);
@@ -7385,7 +7387,9 @@ inline void gcode_M109() {
     #endif
   }
 
-  KEEPALIVE_STATE(IN_HANDLER);
+  #if DISABLED(BUSY_WHILE_HEATING)
+    KEEPALIVE_STATE(IN_HANDLER);
+  #endif
 }
 
 #if HAS_TEMP_BED
@@ -7429,7 +7433,9 @@ inline void gcode_M109() {
     wait_for_heatup = true;
     millis_t now, next_temp_ms = 0, next_cool_check_ms = 0;
 
-    KEEPALIVE_STATE(NOT_BUSY);
+    #if DISABLED(BUSY_WHILE_HEATING)
+      KEEPALIVE_STATE(NOT_BUSY);
+    #endif
 
     target_extruder = active_extruder; // for print_heaterstates
 
@@ -7504,7 +7510,9 @@ inline void gcode_M109() {
     } while (wait_for_heatup && TEMP_BED_CONDITIONS);
 
     if (wait_for_heatup) LCD_MESSAGEPGM(MSG_BED_DONE);
-    KEEPALIVE_STATE(IN_HANDLER);
+    #if DISABLED(BUSY_WHILE_HEATING)
+      KEEPALIVE_STATE(IN_HANDLER);
+    #endif
   }
 
 #endif // HAS_TEMP_BED
@@ -8818,11 +8826,15 @@ inline void gcode_M303() {
     if (WITHIN(e, 0, HOTENDS - 1))
       target_extruder = e;
 
-    KEEPALIVE_STATE(NOT_BUSY); // don't send "busy: processing" messages during autotune output
+    #if DISABLED(BUSY_WHILE_HEATING)
+      KEEPALIVE_STATE(NOT_BUSY);
+    #endif
 
     thermalManager.PID_autotune(temp, e, c, u);
 
-    KEEPALIVE_STATE(IN_HANDLER);
+    #if DISABLED(BUSY_WHILE_HEATING)
+      KEEPALIVE_STATE(IN_HANDLER);
+    #endif
   #else
     SERIAL_ERROR_START();
     SERIAL_ERRORLNPGM(MSG_ERR_M303_DISABLED);
diff --git a/Marlin/example_configurations/Anet/A6/Configuration.h b/Marlin/example_configurations/Anet/A6/Configuration.h
index c007dfd8714..93a0ba56419 100644
--- a/Marlin/example_configurations/Anet/A6/Configuration.h
+++ b/Marlin/example_configurations/Anet/A6/Configuration.h
@@ -1158,6 +1158,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/CL-260/Configuration.h b/Marlin/example_configurations/CL-260/Configuration.h
index 368ac8583df..9f0a82ac7ce 100644
--- a/Marlin/example_configurations/CL-260/Configuration.h
+++ b/Marlin/example_configurations/CL-260/Configuration.h
@@ -999,6 +999,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/Cartesio/Configuration.h b/Marlin/example_configurations/Cartesio/Configuration.h
index 18e5c7bbcef..e086f3c96ef 100644
--- a/Marlin/example_configurations/Cartesio/Configuration.h
+++ b/Marlin/example_configurations/Cartesio/Configuration.h
@@ -996,6 +996,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/Felix/Configuration.h b/Marlin/example_configurations/Felix/Configuration.h
index dac548dcd03..a5a060395b0 100644
--- a/Marlin/example_configurations/Felix/Configuration.h
+++ b/Marlin/example_configurations/Felix/Configuration.h
@@ -980,6 +980,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/Felix/DUAL/Configuration.h b/Marlin/example_configurations/Felix/DUAL/Configuration.h
index 9289dafb775..5a9fa518576 100644
--- a/Marlin/example_configurations/Felix/DUAL/Configuration.h
+++ b/Marlin/example_configurations/Felix/DUAL/Configuration.h
@@ -980,6 +980,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/FolgerTech-i3-2020/Configuration.h b/Marlin/example_configurations/FolgerTech-i3-2020/Configuration.h
index 0bc709730d5..9efdf996f2d 100644
--- a/Marlin/example_configurations/FolgerTech-i3-2020/Configuration.h
+++ b/Marlin/example_configurations/FolgerTech-i3-2020/Configuration.h
@@ -1002,6 +1002,7 @@
 //
 //#define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/Hephestos/Configuration.h b/Marlin/example_configurations/Hephestos/Configuration.h
index f5e915c319d..c1501dbc259 100644
--- a/Marlin/example_configurations/Hephestos/Configuration.h
+++ b/Marlin/example_configurations/Hephestos/Configuration.h
@@ -988,6 +988,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/Hephestos_2/Configuration.h b/Marlin/example_configurations/Hephestos_2/Configuration.h
index 31d3e90c484..805ee35ec69 100644
--- a/Marlin/example_configurations/Hephestos_2/Configuration.h
+++ b/Marlin/example_configurations/Hephestos_2/Configuration.h
@@ -991,6 +991,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 10 // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/Infitary-i3-M508/Configuration.h b/Marlin/example_configurations/Infitary-i3-M508/Configuration.h
index 1abb8f8f0ff..10bf51ee9fd 100644
--- a/Marlin/example_configurations/Infitary-i3-M508/Configuration.h
+++ b/Marlin/example_configurations/Infitary-i3-M508/Configuration.h
@@ -985,6 +985,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/K8200/Configuration.h b/Marlin/example_configurations/K8200/Configuration.h
index 170a018fc0c..dfc27e9764c 100644
--- a/Marlin/example_configurations/K8200/Configuration.h
+++ b/Marlin/example_configurations/K8200/Configuration.h
@@ -1027,6 +1027,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/K8400/Configuration.h b/Marlin/example_configurations/K8400/Configuration.h
index e647c8dd2af..65633a76986 100644
--- a/Marlin/example_configurations/K8400/Configuration.h
+++ b/Marlin/example_configurations/K8400/Configuration.h
@@ -998,6 +998,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/K8400/Dual-head/Configuration.h b/Marlin/example_configurations/K8400/Dual-head/Configuration.h
index 4fdebe88aac..16ee469ade8 100644
--- a/Marlin/example_configurations/K8400/Dual-head/Configuration.h
+++ b/Marlin/example_configurations/K8400/Dual-head/Configuration.h
@@ -998,6 +998,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/M150/Configuration.h b/Marlin/example_configurations/M150/Configuration.h
index 9ff8c97bb22..d3d496eaaf8 100644
--- a/Marlin/example_configurations/M150/Configuration.h
+++ b/Marlin/example_configurations/M150/Configuration.h
@@ -1025,6 +1025,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/RepRapWorld/Megatronics/Configuration.h b/Marlin/example_configurations/RepRapWorld/Megatronics/Configuration.h
index 40ce7aee3c9..c6234d6598b 100644
--- a/Marlin/example_configurations/RepRapWorld/Megatronics/Configuration.h
+++ b/Marlin/example_configurations/RepRapWorld/Megatronics/Configuration.h
@@ -998,6 +998,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/RigidBot/Configuration.h b/Marlin/example_configurations/RigidBot/Configuration.h
index a51bfc7cfac..dd88d90ef82 100644
--- a/Marlin/example_configurations/RigidBot/Configuration.h
+++ b/Marlin/example_configurations/RigidBot/Configuration.h
@@ -996,6 +996,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/SCARA/Configuration.h b/Marlin/example_configurations/SCARA/Configuration.h
index f9e9de755f6..a12b3393f0f 100644
--- a/Marlin/example_configurations/SCARA/Configuration.h
+++ b/Marlin/example_configurations/SCARA/Configuration.h
@@ -1010,6 +1010,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/TAZ4/Configuration.h b/Marlin/example_configurations/TAZ4/Configuration.h
index 470a4ad73c2..825e7fab70b 100644
--- a/Marlin/example_configurations/TAZ4/Configuration.h
+++ b/Marlin/example_configurations/TAZ4/Configuration.h
@@ -1017,6 +1017,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/TinyBoy2/Configuration.h b/Marlin/example_configurations/TinyBoy2/Configuration.h
index a5a7cf47e90..07ac3077e72 100644
--- a/Marlin/example_configurations/TinyBoy2/Configuration.h
+++ b/Marlin/example_configurations/TinyBoy2/Configuration.h
@@ -1054,6 +1054,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/WITBOX/Configuration.h b/Marlin/example_configurations/WITBOX/Configuration.h
index 266a1ae2b57..97b628a5fe6 100644
--- a/Marlin/example_configurations/WITBOX/Configuration.h
+++ b/Marlin/example_configurations/WITBOX/Configuration.h
@@ -988,6 +988,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/adafruit/ST7565/Configuration.h b/Marlin/example_configurations/adafruit/ST7565/Configuration.h
index 19f2021c66a..990b0954316 100644
--- a/Marlin/example_configurations/adafruit/ST7565/Configuration.h
+++ b/Marlin/example_configurations/adafruit/ST7565/Configuration.h
@@ -998,6 +998,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/delta/FLSUN/auto_calibrate/Configuration.h b/Marlin/example_configurations/delta/FLSUN/auto_calibrate/Configuration.h
index c336127b33a..ff5c5a7fd62 100644
--- a/Marlin/example_configurations/delta/FLSUN/auto_calibrate/Configuration.h
+++ b/Marlin/example_configurations/delta/FLSUN/auto_calibrate/Configuration.h
@@ -1122,6 +1122,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 5  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/delta/FLSUN/kossel_mini/Configuration.h b/Marlin/example_configurations/delta/FLSUN/kossel_mini/Configuration.h
index eaa3364ee59..f5d02273842 100644
--- a/Marlin/example_configurations/delta/FLSUN/kossel_mini/Configuration.h
+++ b/Marlin/example_configurations/delta/FLSUN/kossel_mini/Configuration.h
@@ -1117,6 +1117,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 5  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/delta/generic/Configuration.h b/Marlin/example_configurations/delta/generic/Configuration.h
index 36ae17e9752..3dcee31c66e 100644
--- a/Marlin/example_configurations/delta/generic/Configuration.h
+++ b/Marlin/example_configurations/delta/generic/Configuration.h
@@ -1107,6 +1107,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/delta/kossel_mini/Configuration.h b/Marlin/example_configurations/delta/kossel_mini/Configuration.h
index c1e6749099a..1880f5ba9b4 100644
--- a/Marlin/example_configurations/delta/kossel_mini/Configuration.h
+++ b/Marlin/example_configurations/delta/kossel_mini/Configuration.h
@@ -1110,6 +1110,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/delta/kossel_pro/Configuration.h b/Marlin/example_configurations/delta/kossel_pro/Configuration.h
index 59fe5dc428a..34ac25c39c0 100644
--- a/Marlin/example_configurations/delta/kossel_pro/Configuration.h
+++ b/Marlin/example_configurations/delta/kossel_pro/Configuration.h
@@ -1115,6 +1115,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/delta/kossel_xl/Configuration.h b/Marlin/example_configurations/delta/kossel_xl/Configuration.h
index 0b682d3d62b..bba2d9d9b11 100644
--- a/Marlin/example_configurations/delta/kossel_xl/Configuration.h
+++ b/Marlin/example_configurations/delta/kossel_xl/Configuration.h
@@ -1173,6 +1173,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/gCreate_gMax1.5+/Configuration.h b/Marlin/example_configurations/gCreate_gMax1.5+/Configuration.h
index 6667ef14738..d7404f47821 100644
--- a/Marlin/example_configurations/gCreate_gMax1.5+/Configuration.h
+++ b/Marlin/example_configurations/gCreate_gMax1.5+/Configuration.h
@@ -1014,6 +1014,7 @@
 //
 //#define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/makibox/Configuration.h b/Marlin/example_configurations/makibox/Configuration.h
index e45e8d2e6a9..0c317fc515f 100644
--- a/Marlin/example_configurations/makibox/Configuration.h
+++ b/Marlin/example_configurations/makibox/Configuration.h
@@ -1001,6 +1001,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/tvrrug/Round2/Configuration.h b/Marlin/example_configurations/tvrrug/Round2/Configuration.h
index 9edc8914cca..ea2aed618df 100644
--- a/Marlin/example_configurations/tvrrug/Round2/Configuration.h
+++ b/Marlin/example_configurations/tvrrug/Round2/Configuration.h
@@ -993,6 +993,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher
diff --git a/Marlin/example_configurations/wt150/Configuration.h b/Marlin/example_configurations/wt150/Configuration.h
index d9c4b4a2f62..7487dcee574 100644
--- a/Marlin/example_configurations/wt150/Configuration.h
+++ b/Marlin/example_configurations/wt150/Configuration.h
@@ -1004,6 +1004,7 @@
 //
 #define HOST_KEEPALIVE_FEATURE        // Disable this if your host doesn't like keepalive messages
 #define DEFAULT_KEEPALIVE_INTERVAL 2  // Number of seconds between "busy" messages. Set with M113.
+#define BUSY_WHILE_HEATING            // Some hosts require "busy" messages even during heating
 
 //
 // M100 Free Memory Watcher