Regardless, clearly the Rep 1.0.x implementation of this feature is a work in progress as is quadratic advance. So as an early Christmas present, I’ll configure a copy of Marlin 2 for y’all to play with today. It’s implementation of Lin advance is slightly different however you should be able to use it out of the box. Marlin 2 is a memory hungry beast though. Not sure if Multi grid bed (distortion) mapping works on the Rumba as it runs out of memory. I’ll try to free up whatever I can by cutting useless features. Gimme a few hours.