Overhang threshold
Where is the max overhang threshold with the MK4S considering it now has better part cooling?
The default in PrusaSlicer is set at 40, can it be safely lowered to 30, considering the printer can do up to 70degree overhangs?
RE: Overhang threshold
There's no real answer to this. It depends on several combined factors : type of filament ( PLA, PETG, ASA etc.. ), geometry of the model, printing speed, nozzle temperature..
I'd say that the best scenario would be : PLA printed at a rather low nozzle temp ( 190-200C), fan at full speed, low(ish) printing speeds,( enabling overhang dynamic speeds helps a lot ). Possibly you'd get decent quality for 30º overhangs, but then some PLAs will perform better than others. so if you want a definite answer, trial and error seems your best friend,
Worse scenario : TPE/TPU, Overhangs/bridges don't make a good couple with flex filaments. Period.