@koconnor I totally agree on the homing side of things. While I can’t admit I fully follow the code (I’ve been digging through it and piecing together a mental model) I know it does result in offsets when probing/homing with a toolhead based probe and multiple z-axis steppers.
I’ve been trying to think of a way to more closely tie the stepper movements together to do like you said, a constant stepper movement not a constant toolhead movement. Because, especially when you try to do things like Quad Gantry Level, that’s what you want. You KNOW the toolhead is in a bad position, you want to know how the steppers are.
I’ve also started poking around in the firmware code for the mcus to see if I can tighen up some of the code to decrease the srtt any to help improve Multi_mcu homing and eventually support Multi_mcu on a shared axis (z).