I'm certainly open to being educated here but I was reasonably convinced by what I was seeing. Have a look at my notes and perhaps you can see where / if I may have misunderstood what was happening:
www.murraye.com/2026/08/improving-homing...acy-on-linuxcnc.html
In my case, with 5um resolution scales and closed loop controls, my final resting position after homing can't be any more accurate than the resolution of the scales allow, so perhaps I've been chasing up a dead end anyway? A positional accuracy of 5 or 10um from true is probably the best I could hope for on a good day.
The PID element was initially due to my controllers being unstable but the homing velocity did seem to impact accuracy too.
