@dc42 Quick update:
I redesigned the housing and re-printed, paying particular attention to having the filament only in contact with the PTFE, having the PTFE securely mounted closest to the hob and passing the filament over the hob such that the idler has very little work to do. I believe RC2 fixed the "sensor error" issue and the housing update seems to have cleared the frequent spurious movement readings I was still getting.
I'm now consistently getting:
Duet3D rotating magnet filament monitor v3 on pin e0stop, enabled, sensitivity 26.67mm/rev, allow 70% to 130%, check printing moves every 6.0mm, version 3, mag 131 agc 69, measured sensitivity 26.69mm/rev, min 98% max 102% over 13106.6mm
Not had an unwelcome print pause in days now.
2022-03-11 13.44.38.jpg
I could probably refine the design a little more. I think a full case with strain relief for the cable(s) would be a definite plus.