After some testing I noticed that at high speed (e.g. outer walls 200 inner walls 350, sparse infill 450, int. solid infill 350, topsurface 200, gap infill 350, travel speed 500) printing the vfa lines go away.
I don’t have new teethed pulleys or any other upgrade.
I am very happy with it and want to share this with other K1 max users
I have the setting “slow down for better layer cooling” set at off
wall generator at classic or arachne make no big difference.