Actually nothing to do with the MP3DP.
However, during tinkering with my MPCNC I fried the X-axis on my Ramps 1.4 shield, as I put the driver the wrong way in. The other 4 axis were still running.
Is it possible to shift the X to E1, without tearing the whole firmware apart, so I could still use the board on my Ender 3, which has just 3-axis and 1 Extruder anyways. Eventually switching to TMC 2XXX.