Improve M600 with timeout, wait for heatup.

Marlin/Configuration_adv.h

@@ -721,12 +721,16 @@
   #define FILAMENT_CHANGE_LOAD_LENGTH 0       // Load filament length over hotend in mm
                                               // Longer length for bowden printers to fast load filament into whole bowden tube over the hotend,
                                               // Short or zero length for printers without bowden where loading is not used
-  #define FILAMENT_CHANGE_LOAD_FEEDRATE 10    // Load filament feedrate in mm/s - filament loading into the bowden tube can be fast
+  #define FILAMENT_CHANGE_LOAD_FEEDRATE 6     // Load filament feedrate in mm/s - filament loading into the bowden tube can be fast
   #define FILAMENT_CHANGE_EXTRUDE_LENGTH 50   // Extrude filament length in mm after filament is load over the hotend,
                                               // 0 to disable for manual extrusion
                                               // Filament can be extruded repeatedly from the filament exchange menu to fill the hotend,
                                               // or until outcoming filament color is not clear for filament color change
   #define FILAMENT_CHANGE_EXTRUDE_FEEDRATE 3  // Extrude filament feedrate in mm/s - must be slower than load feedrate
+  #define FILAMENT_CHANGE_NOZZLE_TIMEOUT 45L  // Turn off nozzle if user doesn't change filament within this time limit in seconds
+  #define FILAMENT_CHANGE_NUMBER_OF_ALERT_BEEPS  5L             // Number of alert beeps before printer goes quiet 
+  #define STEPPER_MOTORS_DONT_TIMEOUT_DURING_FILAMENT_CHANGE    // Enable to make stepper motors hold position during filament change even if it 
+                                                                // takes longer than DEFAULT_STEPPER_DEACTIVE_TIME
 #endif
 
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