I think there are two separate things here:
1. Investigate what is different in SWS vs. USB (and even the older WiFi addon)
2. Proper device detection (rotator, focuser, and in the future thermometers, and other features), and not polling devices that are not there.
Task 1 is a technical development task to get to the bottom of why SWS delays responses. Howard gave some clue in the thread I linked to earlier.
Task 2 needs to eventually go into Jasem's repo, because it is the efficient way of doing things. Only 10% or 20% of OnStep users have a rotator, so why make INDI "too chatty" for something that is not there. The focusers are used more, but most users who have them has only one. So why poll the second one? And so on.
I am okay with delaying task 2 until you get to what the underlying issue for task 1. But task 2 must go in for efficiency's sake.