Absorbing heat ?  

RE: Absorbing heat ?

My presumption is it's allowing the chassis of the printer to get to temperature, so any expansion of the metal is complete and therefore stable for the duration of your print

RE: Absorbing heat ?

I added some gcode to skip this step for low temp filaments like PLA and PETG. Not my code originally, but don't remember where I got it from.

G28 ; home all without mesh bed level

;
; Added - No chamber heater for PLA/PETG
;
{if chamber_minimal_temperature[initial_tool] > 36}
; CHAMBER HEATING AND WAIT FOR MATERIALS THAT NEED >36 °C CHAMBER
M104 S{idle_temperature[initial_tool]} ; set idle temp
G1 Z10 F720 ; set bed position
G1 X242 Y-9 F4800 ; set print head position
M191 S{chamber_minimal_temperature[initial_tool]} ; wait for minimal chamber temp
M141 S{chamber_temperature[initial_tool]} ; set nominal chamber temp
M107
M140 S[first_layer_bed_temperature] ; set bed temp
{else}
; SKIP CHAMBER HEATING FOR MATERIALS WITH MINIMAL CHAMBER TEMP ≤ 36 °C (E.G. PLA, PETG)
M141 S0 ; disable chamber heater
{endif}

{if first_layer_bed_temperature[initial_tool]<=60}M106 S70{endif}
G0 Z40 F10000
M104 T{initial_tool} S{if is_nil(idle_temperature[initial_tool])}100{else}{idle_temperature[initial_tool]}{endif}
M190 R[first_layer_bed_temperature] ; wait for bed temp
M107

;
; Added - No soak for PLA/PETG
;
{if chamber_minimal_temperature[initial_tool] > 36}
G29 G ; ABSORB HEAT FOR HIGH-TEMP MATERIALS
{else}
G4 S5 ; SHORT PAUSE INSTEAD OF SOAK FOR LOW-TEMP MATERIALS
{endif}