If the primary focusing did not seem optimal - make sure you were doing the autofocus as I describe above: The focus curve should be taken in the counter-clockwise direction, and there should be at least about 1/2 turn of the knob for backlash compensation. And, of course, the backlash compensation should only kick in when you need to turn the knob clockwise - which happens at the start of the autofocus curve.
Focusing by turning the knob ccw is advice given to any new owner of an sct, and it applies also for visual use with no stepper motor at all. Adding a motor doesn't change this requirement - that the mirror should be pushed up against gravity in the final focusing movement.
Frank