Yes, I just tested your suggestion and can confirm that the Autosync Threshold also applies when not slaved. Our telescope would probably need a higher threshold because the amount of slip which the dome experiences seems to vary strongly with temperature.
I can also confirm the limits you spoke of, though I can not give specific numbers. Yours do definitely seem plausible, but the results I found are somewhat mixed. I could throw some numbers around but that would probably not be of much help to anyone else. The main issue here, I believe, is again that our dome slips and needs regular recalibration, depending on weather (or rather temperature) fluctuations.
There was one odd thing we found while testing. We used the INDI starter program to communicate with the module. What we found was that the "Dome CW" and "Dome CCW" buttons seem to crash the program so that one must disconnect the and reconnect in order to regain control over the client. If it helps, the terminal output can be found in the attached file. If I read the documentation correctly, I assume that is because the "DOME_CW" and "DOME_CCW" attributes are not implemented?
And I was also surprised that the dome move in CW direction if you set "DOME_RELATIVE_POSITION" to a value less than -180 deg and in CCW direction for values greater than +180 deg even though the documentation says

Positive degree is clock-wise direction. Negative degrees is counter clock-wise direction.