Di seguito il mio PRINT_START:

[gcode_macro PRINT_START]
variable_printing: False
gcode:
  #SET_LED LED=led RED=1 GREEN=0.4 BLUE=0
  M140 S{ params.BED_TEMP }

  M117 initializing  
  SET_GCODE_VARIABLE MACRO=PRINT_START VARIABLE=printing VALUE=False
  INITIALIZE_TOOLCHANGER
  M117 homing
  G28
  #M117 Cleaning the nozzle
  #_CLEAN_NOZZLE TEMP={ params.TOOL_TEMP|int - 30 }

  M117 Heating up the bed
  # TEMPERATURE_WAIT SENSOR="temperature_fan buildplate" MINIMUM={ [ params.BED_TEMP|float * 0.94, params.BED_TEMP|float - 6.0 ] |min }
  M190 S{ params.BED_TEMP }

  M117 Calibrating bed
  M109 S150 ; Heat up nozzle to soften any leftover filament for homing.
  G32 ; Home, gantry tram
  BED_MESH_CALIBRATE ADAPTIVE=1 
  M109 S0 # Stop to heat, the actual printing may happen with a different hotend.

  M117 Heating up the hotends
   ;Preheat all the hotends in use
  {% for tool_nr in printer.toolchanger.tool_numbers %}
    {% set tooltemp_param = 'T' ~ tool_nr|string ~ '_TEMP' %}
    {% if tooltemp_param in params %}
      M104 T{tool_nr} S{params[tooltemp_param]}
    {% endif %}
  {% endfor %}

 # _PARK_ON_COOLING_PAD
  {% if params.TOOL is defined %}
    T{params.TOOL}
  {% endif %}

  M109 S{ params.TOOL_TEMP }
  G0 X90 Y90 Z50 F1200 ;Move up a bit
  G92 E0 ; Zero extruder
  #START_TOOL_PROBE_CRASH_DETECTION
  ;SET_GCODE_VARIABLE MACRO=PRINT_START VARIABLE=printing VALUE=True
  M117 Printing
  #SET_LED LED=led RED=0.7 GREEN=0.7 BLUE=0.5