Hello Kinch/Jared, thank you very much!
I knew I was missing something obvious..setting rotation to 270 (camera in landscape mode when pointing north in parked position), I got exactly a precise preview of rotation, allowing me to rotate the camera as needed even before starting the session.
I see for more precise rotation I can use indeed the Manual Rotator, that will be step 2, for now usually rotating it 'roughly' is always good enough.
Thanks again for the quick/simple reply 