diff --git a/Marlin/Configuration_adv.h b/Marlin/Configuration_adv.h
index cd58c6e10d..964a2c104a 100644
--- a/Marlin/Configuration_adv.h
+++ b/Marlin/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/default/Configuration_adv.h b/Marlin/src/config/default/Configuration_adv.h
index cd58c6e10d..964a2c104a 100644
--- a/Marlin/src/config/default/Configuration_adv.h
+++ b/Marlin/src/config/default/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/AlephObjects/TAZ4/Configuration_adv.h b/Marlin/src/config/examples/AlephObjects/TAZ4/Configuration_adv.h
index 074edfca3a..b2dbe6e1c7 100644
--- a/Marlin/src/config/examples/AlephObjects/TAZ4/Configuration_adv.h
+++ b/Marlin/src/config/examples/AlephObjects/TAZ4/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/Anet/A6/Configuration_adv.h b/Marlin/src/config/examples/Anet/A6/Configuration_adv.h
index ae63fb9df1..b375a0d7bb 100644
--- a/Marlin/src/config/examples/Anet/A6/Configuration_adv.h
+++ b/Marlin/src/config/examples/Anet/A6/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/Anet/A8/Configuration_adv.h b/Marlin/src/config/examples/Anet/A8/Configuration_adv.h
index f0b93b9cce..7a502d1b87 100644
--- a/Marlin/src/config/examples/Anet/A8/Configuration_adv.h
+++ b/Marlin/src/config/examples/Anet/A8/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/Azteeg/X5GT/Configuration_adv.h b/Marlin/src/config/examples/Azteeg/X5GT/Configuration_adv.h
index cd58c6e10d..964a2c104a 100644
--- a/Marlin/src/config/examples/Azteeg/X5GT/Configuration_adv.h
+++ b/Marlin/src/config/examples/Azteeg/X5GT/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
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 ce1787d707..8cfdb518d0 100644
--- a/Marlin/src/config/examples/BIBO/TouchX/cyclops/Configuration_adv.h
+++ b/Marlin/src/config/examples/BIBO/TouchX/cyclops/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
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 f1b1cad8ab..e358b7ff9e 100644
--- a/Marlin/src/config/examples/BIBO/TouchX/default/Configuration_adv.h
+++ b/Marlin/src/config/examples/BIBO/TouchX/default/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/BQ/Hephestos/Configuration_adv.h b/Marlin/src/config/examples/BQ/Hephestos/Configuration_adv.h
index cce42c75e3..0f15c138ff 100644
--- a/Marlin/src/config/examples/BQ/Hephestos/Configuration_adv.h
+++ b/Marlin/src/config/examples/BQ/Hephestos/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
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 b3e08e2775..7222f3c552 100644
--- a/Marlin/src/config/examples/BQ/Hephestos_2/Configuration_adv.h
+++ b/Marlin/src/config/examples/BQ/Hephestos_2/Configuration_adv.h
@@ -1730,4 +1730,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/BQ/WITBOX/Configuration_adv.h b/Marlin/src/config/examples/BQ/WITBOX/Configuration_adv.h
index cce42c75e3..0f15c138ff 100644
--- a/Marlin/src/config/examples/BQ/WITBOX/Configuration_adv.h
+++ b/Marlin/src/config/examples/BQ/WITBOX/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/Cartesio/Configuration_adv.h b/Marlin/src/config/examples/Cartesio/Configuration_adv.h
index 5c0b1690bf..c10546db20 100644
--- a/Marlin/src/config/examples/Cartesio/Configuration_adv.h
+++ b/Marlin/src/config/examples/Cartesio/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
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 f4db5dbeaf..29367eefba 100755
--- a/Marlin/src/config/examples/Creality/CR-10/Configuration_adv.h
+++ b/Marlin/src/config/examples/Creality/CR-10/Configuration_adv.h
@@ -1725,4 +1725,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
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 5a45bc2c49..e4c439ac08 100644
--- a/Marlin/src/config/examples/Creality/CR-10S/Configuration_adv.h
+++ b/Marlin/src/config/examples/Creality/CR-10S/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
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 6f89cf635a..8b2e9103d9 100644
--- a/Marlin/src/config/examples/Creality/CR-10mini/Configuration_adv.h
+++ b/Marlin/src/config/examples/Creality/CR-10mini/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
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 4458376d7c..6d63e7c8a5 100644
--- a/Marlin/src/config/examples/Creality/CR-8/Configuration_adv.h
+++ b/Marlin/src/config/examples/Creality/CR-8/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
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 d1ef61dae4..f273d8c825 100644
--- a/Marlin/src/config/examples/Creality/Ender-2/Configuration_adv.h
+++ b/Marlin/src/config/examples/Creality/Ender-2/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
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 1243b2d5ee..e46d53e0b8 100644
--- a/Marlin/src/config/examples/Creality/Ender-3/Configuration_adv.h
+++ b/Marlin/src/config/examples/Creality/Ender-3/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
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 4458376d7c..6d63e7c8a5 100644
--- a/Marlin/src/config/examples/Creality/Ender-4/Configuration_adv.h
+++ b/Marlin/src/config/examples/Creality/Ender-4/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/Felix/Configuration_adv.h b/Marlin/src/config/examples/Felix/Configuration_adv.h
index e5bde478b6..2a102f8055 100644
--- a/Marlin/src/config/examples/Felix/Configuration_adv.h
+++ b/Marlin/src/config/examples/Felix/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
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 086507c806..8cba5f3e90 100644
--- a/Marlin/src/config/examples/FolgerTech/i3-2020/Configuration_adv.h
+++ b/Marlin/src/config/examples/FolgerTech/i3-2020/Configuration_adv.h
@@ -1730,4 +1730,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
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 7ea6d77256..540c4e32fa 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	
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
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 7ea6d77256..540c4e32fa 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	
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
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 5e81709af8..26fd198fce 100644
--- a/Marlin/src/config/examples/Infitary/i3-M508/Configuration_adv.h
+++ b/Marlin/src/config/examples/Infitary/i3-M508/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/JGAurora/A5/Configuration_adv.h b/Marlin/src/config/examples/JGAurora/A5/Configuration_adv.h
index e37cae980d..93b9e79008 100644
--- a/Marlin/src/config/examples/JGAurora/A5/Configuration_adv.h
+++ b/Marlin/src/config/examples/JGAurora/A5/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/MakerParts/Configuration_adv.h b/Marlin/src/config/examples/MakerParts/Configuration_adv.h
index 5d95bdf785..8a3cd6eb60 100644
--- a/Marlin/src/config/examples/MakerParts/Configuration_adv.h
+++ b/Marlin/src/config/examples/MakerParts/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/Malyan/M150/Configuration_adv.h b/Marlin/src/config/examples/Malyan/M150/Configuration_adv.h
index 0ad6b45c4e..3a16ec5b35 100644
--- a/Marlin/src/config/examples/Malyan/M150/Configuration_adv.h
+++ b/Marlin/src/config/examples/Malyan/M150/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/Malyan/M200/Configuration_adv.h b/Marlin/src/config/examples/Malyan/M200/Configuration_adv.h
index ed0323981f..7ad114f9ca 100644
--- a/Marlin/src/config/examples/Malyan/M200/Configuration_adv.h
+++ b/Marlin/src/config/examples/Malyan/M200/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
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 faef3301bf..ea352b6a56 100644
--- a/Marlin/src/config/examples/Micromake/C1/enhanced/Configuration_adv.h
+++ b/Marlin/src/config/examples/Micromake/C1/enhanced/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/Mks/Sbase/Configuration_adv.h b/Marlin/src/config/examples/Mks/Sbase/Configuration_adv.h
index 1cf7c56ed3..6a65760c40 100644
--- a/Marlin/src/config/examples/Mks/Sbase/Configuration_adv.h
+++ b/Marlin/src/config/examples/Mks/Sbase/Configuration_adv.h
@@ -1730,4 +1730,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/RigidBot/Configuration_adv.h b/Marlin/src/config/examples/RigidBot/Configuration_adv.h
index 88cf7dd465..732a8051cb 100644
--- a/Marlin/src/config/examples/RigidBot/Configuration_adv.h
+++ b/Marlin/src/config/examples/RigidBot/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/SCARA/Configuration_adv.h b/Marlin/src/config/examples/SCARA/Configuration_adv.h
index d6b99235f7..a3d822e879 100644
--- a/Marlin/src/config/examples/SCARA/Configuration_adv.h
+++ b/Marlin/src/config/examples/SCARA/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/Sanguinololu/Configuration_adv.h b/Marlin/src/config/examples/Sanguinololu/Configuration_adv.h
index daf7359e33..363954706b 100644
--- a/Marlin/src/config/examples/Sanguinololu/Configuration_adv.h
+++ b/Marlin/src/config/examples/Sanguinololu/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/TheBorg/Configuration_adv.h b/Marlin/src/config/examples/TheBorg/Configuration_adv.h
index 60c8f4270d..44a4b842d6 100644
--- a/Marlin/src/config/examples/TheBorg/Configuration_adv.h
+++ b/Marlin/src/config/examples/TheBorg/Configuration_adv.h
@@ -1723,4 +1723,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/TinyBoy2/Configuration_adv.h b/Marlin/src/config/examples/TinyBoy2/Configuration_adv.h
index c44ae7e9b2..31606428e3 100644
--- a/Marlin/src/config/examples/TinyBoy2/Configuration_adv.h
+++ b/Marlin/src/config/examples/TinyBoy2/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/UltiMachine/Archim2/Configuration_adv.h b/Marlin/src/config/examples/UltiMachine/Archim2/Configuration_adv.h
index 807b926d43..360ea1f2a4 100644
--- a/Marlin/src/config/examples/UltiMachine/Archim2/Configuration_adv.h
+++ b/Marlin/src/config/examples/UltiMachine/Archim2/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/Velleman/K8200/Configuration_adv.h b/Marlin/src/config/examples/Velleman/K8200/Configuration_adv.h
index 2dac78cea2..7ff16a271e 100644
--- a/Marlin/src/config/examples/Velleman/K8200/Configuration_adv.h
+++ b/Marlin/src/config/examples/Velleman/K8200/Configuration_adv.h
@@ -1725,4 +1725,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/Velleman/K8400/Configuration_adv.h b/Marlin/src/config/examples/Velleman/K8400/Configuration_adv.h
index f8fb9dd2e0..7a04202e57 100644
--- a/Marlin/src/config/examples/Velleman/K8400/Configuration_adv.h
+++ b/Marlin/src/config/examples/Velleman/K8400/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
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 8c2fd913a4..49a4983a37 100644
--- a/Marlin/src/config/examples/Wanhao/Duplicator 6/Configuration_adv.h	
+++ b/Marlin/src/config/examples/Wanhao/Duplicator 6/Configuration_adv.h	
@@ -1724,4 +1724,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
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 02af9293f2..123fe92494 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
@@ -1724,4 +1724,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
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 68ec1a6755..ebce1fe581 100644
--- a/Marlin/src/config/examples/delta/FLSUN/kossel/Configuration_adv.h
+++ b/Marlin/src/config/examples/delta/FLSUN/kossel/Configuration_adv.h
@@ -1724,4 +1724,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
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 86651be99d..5eedc749ab 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
@@ -1724,4 +1724,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/delta/generic/Configuration_adv.h b/Marlin/src/config/examples/delta/generic/Configuration_adv.h
index 86651be99d..5eedc749ab 100644
--- a/Marlin/src/config/examples/delta/generic/Configuration_adv.h
+++ b/Marlin/src/config/examples/delta/generic/Configuration_adv.h
@@ -1724,4 +1724,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
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 86651be99d..5eedc749ab 100644
--- a/Marlin/src/config/examples/delta/kossel_mini/Configuration_adv.h
+++ b/Marlin/src/config/examples/delta/kossel_mini/Configuration_adv.h
@@ -1724,4 +1724,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/delta/kossel_pro/Configuration_adv.h b/Marlin/src/config/examples/delta/kossel_pro/Configuration_adv.h
index 6585badbe2..b3d4e887df 100644
--- a/Marlin/src/config/examples/delta/kossel_pro/Configuration_adv.h
+++ b/Marlin/src/config/examples/delta/kossel_pro/Configuration_adv.h
@@ -1729,4 +1729,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
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 c294ee710e..50012d5403 100644
--- a/Marlin/src/config/examples/delta/kossel_xl/Configuration_adv.h
+++ b/Marlin/src/config/examples/delta/kossel_xl/Configuration_adv.h
@@ -1724,4 +1724,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
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 e6432d98ab..319bb9632c 100644
--- a/Marlin/src/config/examples/gCreate/gMax1.5+/Configuration_adv.h
+++ b/Marlin/src/config/examples/gCreate/gMax1.5+/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/makibox/Configuration_adv.h b/Marlin/src/config/examples/makibox/Configuration_adv.h
index a945585fae..ea907a40e1 100644
--- a/Marlin/src/config/examples/makibox/Configuration_adv.h
+++ b/Marlin/src/config/examples/makibox/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/tvrrug/Round2/Configuration_adv.h b/Marlin/src/config/examples/tvrrug/Round2/Configuration_adv.h
index f74a81506f..9e85785b78 100644
--- a/Marlin/src/config/examples/tvrrug/Round2/Configuration_adv.h
+++ b/Marlin/src/config/examples/tvrrug/Round2/Configuration_adv.h
@@ -1722,4 +1722,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/config/examples/wt150/Configuration_adv.h b/Marlin/src/config/examples/wt150/Configuration_adv.h
index 03b0efcae3..ff2942212d 100644
--- a/Marlin/src/config/examples/wt150/Configuration_adv.h
+++ b/Marlin/src/config/examples/wt150/Configuration_adv.h
@@ -1723,4 +1723,7 @@
   #define WIFI_PWD  "Wifi Password"
 #endif
 
+// Enable Marlin dev mode which adds some special commands
+//#define MARLIN_DEV_MODE
+
 #endif // CONFIGURATION_ADV_H
diff --git a/Marlin/src/gcode/calibrate/G28.cpp b/Marlin/src/gcode/calibrate/G28.cpp
index 26cf2b0974..d88fd91bf7 100644
--- a/Marlin/src/gcode/calibrate/G28.cpp
+++ b/Marlin/src/gcode/calibrate/G28.cpp
@@ -174,6 +174,19 @@ void GcodeSuite::G28(const bool always_home_all) {
     }
   #endif
 
+  #if ENABLED(MARLIN_DEV_MODE)
+    if (parser.seen('S')) {
+      LOOP_XYZ(a) set_axis_is_at_home((AxisEnum)a);
+      SYNC_PLAN_POSITION_KINEMATIC();
+      SERIAL_ECHOLNPGM("Simulated Homing");
+      report_current_position();
+      #if ENABLED(DEBUG_LEVELING_FEATURE)
+        if (DEBUGGING(LEVELING)) SERIAL_ECHOLNPGM("<<< G28");
+      #endif
+      return;
+    }
+  #endif
+
   if (all_axes_known() && parser.boolval('O')) { // home only if needed
     #if ENABLED(DEBUG_LEVELING_FEATURE)
       if (DEBUGGING(LEVELING)) {