My main imaging camera is an Olympus Em-5. It does not tether with software to control exposure. I do not know a way if the images could be downloaded from the cam to Rpi4.
The guide cam is a ASI224MC and the guide scope is this:
I do not have a captured image with it but I did not notice any star deformation on this scope.
I do understand star deformation, I had that issue with a guide scope before, stars looked horrible and made guiding more difficult as well. This one is pretty good.