Here is a thread where I describe it in some detail - and the developers talk about implementing it. That was from last year:
When new versions came out I immediately tested them with cge-pro - but they didn’t seem to work. Since then I have seen numerous people with Celestron mounts ask about Center not converging - and instead getting stuck - so if you try the various options and they don’t seem to work - and if you do feel you need more accurate centering - then that would be good info.
It may seem like 1’ accuracy is adequate for most needs - but a) for long focal length work the lack of accuracy makes the mosaic tool less useful and you need to plan larger overlap and b) a big part of what sgp does is get high performance from a system of medium performance tools - and accurate centering with a plate solve is a good example of it.
Frank