Maybe there is a way to resolve this already, but I have not seen it.
Problem. After many ditherings, the target can be quite a bit away from where it started.
Often, it's not a problem, as it's not off by much, and my target is centered anyway.
But occasionally, on very large subjects, I can find that dithering moves a critical star or object that was on the edge of the frame off the edge.
Solution: After a set amount of ditherings (user controlled), EKOS performs a re-alignment using the very first image in the session as the reference image.
Right now, it's hardcoded to wander a maximum of about 25 pixels. Have you seen it stray more than that? I guess I should make this value configurable.