I addressed this topic in this thread:
In the case of a rotator used to find an OAG guidestar, the sky angle is secondary and you just want the rotator angle set exactly. You can do this with the optec rotator by using its own sync function to match its angle reading with the PA of the OAG.
Unfortunately I think that after it solves an image once, SGP will from then on use the sky angle to set the rotator for the next image - which is not what you want if the oag angle is slightly off from the image angle - which it often is. SGP figures out the offset of the sky angle from the rotator angle and corrects it for you - even if you just want to set the true rotator angle. So I think that the only way you can accurately set a sequence of images for a particular guidestar angle is if you mechanically match the oag angle with the sky angle - which is hard to do in my case since there is no fine control on setting the image angle - and you would want it to a fraction of a degree.
It is also often the case that for different images you would manually orient the imaging camera to frame the object - while using the rotator to set the guidestar. This would be a manual step for each object. A typical case would be to set the oag angle exactly for the guidestar - and then orient the camera approximately with north up. In all this the idea is that finding the guidestar is critical - but the image orientation doesn't need to be exact. That isn't the case for mosaics, but it is the case for a lot of imaging.
As for multiple connections to the rotator - Optec has an ascom hub that should allow this to work. I'm not sure why it isn't built into the ascom driver - but I think it would work.
http://www.optecinc.com/astronomy/downloads/ascom_server.htm
Frank