This is something I've seen a number of times and wondering if there isn't a way for ACP to see that the rotator has reached it's limit and is resetting?
No I have no way to tell if the rotator is having problems and needs to "reset".

I know we're likely to lose a frame as ACP can't see that the rotator being used as a derotator and camera rotator is at ot reaching it's limit but when the rotator is commanded by ACP to go to a camera PA of course it's aware but what about as a derotator? Any idea how other rotators used this way handle this? John has a call into Jeff at Optec to see if there is a solution or at least an optimal way to handle this but my thinking with both derotation and camera PA the best we can hope for is a paused between image acquiring if ACP sees the rotator is busy with either function.
I can't be involved in any of this. ACP tells the rotator to go to a mechanical position (based on my past experience of the difference between mechanical angle and actual/true-sky PA). I always wait for the rotator to tell me it has reached the requested angle.

Last night was an example while the rotator was resetting ACP was taking a pointing update image and of course the pointing update failed as expected. Just trying to figure a way to minimize this effect if possible. Dr. Crass ahs seen and asked about this as well.
I have no way to mitigate this problem with the rotator becoming confused between its job of derotating for the alt/az angle and responding to my requests to position at a given angle with respect to the equatorial coordinate system. Again I do know that there can be a difference between the mechanical camera angle against the equatorial coordinate system and the actual image position angle against the equatorial coordinate system, and I measure and correct for that. I have no way to become involved in wrap limits, etc. No way. The standard Rotator interface purposely guards clients like me from having to become involved in that sort of thing.

Policy for Working Around Device Errors, Quirks, and Limitations