I understand that the patch of the Ascom Camera Simulator is not a trivial task to do.
But since a real CCD camera driver can do it, it would be possible to prepare a second image (subframe) by cropping the skySimulator already calculated image to 128x128 around the star.
It surely need some of good reading / code review of actual simulator or camera drivers...
I will maybe invest some time to clarify this, but for now i'm too busy with our next observatory.
This windows platform is not in my confort zone either, i usually run linux and do some tiny code in ruby/golang...
Thank you for your prompt answer