I just took the switches off and spend 2hours making sure the switch stops were square. I hold the gantry against the stops then go .01 and back to 0 to lock everything.
I found they would activate at inconsistent places, sometimes the arm would bend or even fall off without me noticing.
I checked it with the manual stops and I’m .1mm differe ce side to side across 36in.
The downside is without telling the board the home location sometimes it tries to go beyond 0. I might just add a button for a manual end stop.
Using the skr setup
That is nuts, but awesome to hear how accurate you are by hand!
My understanding is that arm increases the accuracy as long as you come at it slow enough. +/-0.01mm should be easy to hit with either end stop, I Wonder if you are getting some line noise or something.