Welp, I'm farther back than I was before, with no reason as to why.
All of a sudden tonight I'm getting a huge number of mount I/O errors and timeout errors, it won't slew correctly, can't even set initial calibration to guide now.
Nothing I've done differently, in fact I even shelled out for a powered hub which seemed to solve the problem, also got a fancy USB cable just for the absurdity of the GEM45 mount. Even had a few nights with superb guiding, images, etc.
Now it's every ~5s I get an I/O error and timeout errors; nothing has changed, I'm even using the same USB ports...
Honestly, I don't even have the heart to keep fooling with it at this point; I'm going to try to reach out to iOptron but they've not returned any emails, otherwise I may try to initiate a return and get a NUC or something. Not enough painkillers in the world to deal with this headache at this point, seemingly purely based on the whims of fate.