diff --git a/Marlin/Configuration_adv.h b/Marlin/Configuration_adv.h
index ecc6f9dd8..2c9ac1aea 100644
--- a/Marlin/Configuration_adv.h
+++ b/Marlin/Configuration_adv.h
@@ -637,6 +637,9 @@
 
   // Default x offset in duplication mode (typically set to half print bed width)
   #define DEFAULT_DUPLICATION_X_OFFSET 100
+
+  // Default action to execute following M605 mode change commands. Typically G28X to apply new mode.
+  //#define EVENT_GCODE_IDEX_AFTER_MODECHANGE "G28X"
 #endif
 
 // Activate a solenoid on the active extruder with M380. Disable all with M381.
diff --git a/Marlin/src/gcode/control/M605.cpp b/Marlin/src/gcode/control/M605.cpp
index b1e54b25e..0d7a9f431 100644
--- a/Marlin/src/gcode/control/M605.cpp
+++ b/Marlin/src/gcode/control/M605.cpp
@@ -103,6 +103,10 @@
       }
       idex_set_parked(false);
       set_duplication_enabled(false);
+
+      #ifdef EVENT_GCODE_IDEX_AFTER_MODECHANGE
+        gcode.process_subcommands_now_P(PSTR(EVENT_GCODE_IDEX_AFTER_MODECHANGE));
+      #endif
     }
     else if (!parser.seen('W'))  // if no S or W parameter, the DXC mode gets reset to the user's default
       dual_x_carriage_mode = DEFAULT_DUAL_X_CARRIAGE_MODE;
diff --git a/Marlin/src/lcd/language/language_en.h b/Marlin/src/lcd/language/language_en.h
index d14880d97..4231eca5c 100644
--- a/Marlin/src/lcd/language/language_en.h
+++ b/Marlin/src/lcd/language/language_en.h
@@ -144,6 +144,7 @@ namespace Language_en {
   PROGMEM Language_Str MSG_IDEX_MODE_DUPLICATE             = _UxGT("Duplication");
   PROGMEM Language_Str MSG_IDEX_MODE_MIRRORED_COPY         = _UxGT("Mirrored Copy");
   PROGMEM Language_Str MSG_IDEX_MODE_FULL_CTRL             = _UxGT("Full Control");
+  PROGMEM Language_Str MSG_IDEX_DUPE_GAP                   = _UxGT("Duplicate X-Gap");
   PROGMEM Language_Str MSG_HOTEND_OFFSET_X                 = _UxGT("2nd Nozzle X");
   PROGMEM Language_Str MSG_HOTEND_OFFSET_Y                 = _UxGT("2nd Nozzle Y");
   PROGMEM Language_Str MSG_HOTEND_OFFSET_Z                 = _UxGT("2nd Nozzle Z");
diff --git a/Marlin/src/lcd/menu/menu_configuration.cpp b/Marlin/src/lcd/menu/menu_configuration.cpp
index f667242bc..2c3af1e5e 100644
--- a/Marlin/src/lcd/menu/menu_configuration.cpp
+++ b/Marlin/src/lcd/menu/menu_configuration.cpp
@@ -194,16 +194,19 @@ void menu_advanced_settings();
     START_MENU();
     BACK_ITEM(MSG_CONFIGURATION);
 
-    GCODES_ITEM(MSG_IDEX_MODE_AUTOPARK,  PSTR("M605 S1\nG28 X\nG1 X100"));
+    GCODES_ITEM(MSG_IDEX_MODE_AUTOPARK,  PSTR("M605S1\nG28X\nG1X0"));
     GCODES_ITEM(MSG_IDEX_MODE_DUPLICATE, need_g28
-      ? PSTR("M605 S1\nT0\nG28\nM605 S2 X200\nG28 X\nG1 X100")                // If Y or Z is not homed, do a full G28 first
-      : PSTR("M605 S1\nT0\nM605 S2 X200\nG28 X\nG1 X100")
+      ? PSTR("M605S1\nT0\nG28\nM605S2\nG28X\nG1X0")         // If Y or Z is not homed, do a full G28 first
+      : PSTR("M605S1\nT0\nM605S2\nG28X\nG1X0")
     );
     GCODES_ITEM(MSG_IDEX_MODE_MIRRORED_COPY, need_g28
-      ? PSTR("M605 S1\nT0\nG28\nM605 S2 X200\nG28 X\nG1 X100\nM605 S3 X200")  // If Y or Z is not homed, do a full G28 first
-      : PSTR("M605 S1\nT0\nM605 S2 X200\nG28 X\nG1 X100\nM605 S3 X200")
+      ? PSTR("M605S1\nT0\nG28\nM605S2\nG28X\nG1X0\nM605S3") // If Y or Z is not homed, do a full G28 first
+      : PSTR("M605S1\nT0\nM605S2\nG28 X\nG1X0\nM605S3")
     );
-    GCODES_ITEM(MSG_IDEX_MODE_FULL_CTRL, PSTR("M605 S0\nG28 X"));
+    GCODES_ITEM(MSG_IDEX_MODE_FULL_CTRL, PSTR("M605S0\nG28X"));
+
+    EDIT_ITEM(float42_52, MSG_IDEX_DUPE_GAP, &duplicate_extruder_x_offset, (X2_MIN_POS) - (X1_MIN_POS), (X_BED_SIZE) - 20);
+
     END_MENU();
   }
 
diff --git a/buildroot/tests/mega2560-tests b/buildroot/tests/mega2560-tests
index 9ae43dcdb..cc9830be3 100755
--- a/buildroot/tests/mega2560-tests
+++ b/buildroot/tests/mega2560-tests
@@ -259,10 +259,10 @@ exec_test $1 $2 "Mightyboard Rev. E | CoreXY, Gradient Mix | Endstop Int. | Home
 
 ######## Example Configurations ##############
 #
-# Test a full-featured CR-10S config
+# Test a basic DUAL_X_CARRIAGE configuration
 #
-use_example_configs Creality/CR-10S
-exec_test $1 $2 "Full-featured CR-10S config"
+use_example_configs Formbot/T_Rex_3
+exec_test $1 $2 "Formbot/T_Rex_3 example configuration."
 
 #
 # BQ Hephestos 2