Basically it should set the bed temp first and wait, then set the extruder temp and wait, then check and wait for the bed temp the starts the homing without mesh then mesh bed leveling then finally at home position it will heat up the extruder to the defined extruder temp I set in the profile which is 218 then proceed with the bubble purge and intro line.
Running Prusa mk3s with Bondtech Firmware 3.8.1, S3D v4.1.2
M115 U3.8.1 ; tell printer latest fw version
M140 S[first_layer_bed_temperature] ; set bed temp
M109 S170 ; set extruder temp
M190 S[first_layer_bed_temperature] ; wait for bed temp
G28 W ; home all without mesh bed level
G80 ; mesh bed leveling
M109 S[first_layer_temperature] ; wait for extruder temp
G1 Y-3.0 F1000.0 ; go outside printing area
G92 E0.0
G1 E6 ; Purge Bubble
G1 X60.0 E9.0 F1000.0 ; intro line
G1 X100.0 E12.5 F1000.0 ; intro line
G92 E0.0
M221 S{if layer_height<0.075}100{else}95{endif}
M900 K30 ; Linear Advance PLA
