Hello, I was not totally convinced by the use of Marlin on MPCNC (it does not interpret certain gcodes), and I discovered a version of GRBL compatible with RAMPS (GRBL 5X) is being developed. I modified the code to get the same wiring on Ramps (Autosquare include). I also have the necessary configuration of GRBL what let everything works. I am testing it with Universal Gcode sender and it works really well. Saves positions (G28-G30), all calibration plate options works and interprets most of professional programas gcodes. If you are interested in trying it, I will be happy to share it .
Regards from Spain.