another issue that maybe you can comment on:

Two nights ago, when I had tested the new version, I had put my guide camera in 2x2 bin mode and forgot to set it back.  During that session, I had some really weird (and bad) guiding errors.  Guiding would be great, until suddenly it would start to oscillate:

Those excursions came back several times (roughly half an hour spaced), so I assumed there might be something with the belt of the RA axis.
It went away after the meridian flip.
Last night, I got a similar behavior right from the start.  What I had noticed was that the jump/error was about 3 arc sec, which is the (binned) pixel size of the guide cam, and RA and DEC were basically in anti-phase... that really looked artificial to me.
I switched back to 1x1 binning, and the problem was gone.
Now I wonder if anything in the code could trigger such an error, or if maybe the binning algorithm is unstable somehow. Or do you have other ideas?
This is an ASI1600MM.  I use multistar SEP/guide profile and GPG.