Following up:
Tech did arrive 30 minutes after he called (split the difference between our estimates). He couldn't do anything for my primary issue because the severity I described wasn't communicated to him and it needs to be handled at a Service Center. The remaining issues were explained away as known issues that will probably never get fixed (wifi antennas are inadequate), known issues that may be fixed in upcoming firmware or might need a higher level fix (programmers fixing something broke something else so just wait and they'll fix that), or something that sure seems wonky but...
He was a very nice guy but nothing got done after I was chained to my home for 5 hours. If I'd taken my car to the SC, I would've left it there and gone about my day. Same thing at GM, Ford, Honda, my local mechanic, etc. so I'm not impressed with the Mobile Service experience. Sure, if I worked a 9-5 gig and they could work on it in the employee parking lot, I could see the appeal just like getting a windshield repair done on site. For me, that isn't the case. Either they have to come to my house and access my garage or, if I bothered driving to work rather than taking the train, they'd have to be escorted into the secured parking lot by somebody other than me.
Another thing the tech said he's been trying to convince those in charge about is that they've been scheduling too many calls within the call out windows and not enough time between them to actually make it even without the continuous rush hour we now deal with in Chicago. You'd think the Californians would be on the same page about traffic but it sure seems like they've got a former Amazon warehouse scheduler running the show.
It'll be interesting to see if I ever get a response to the e-mail. The tech invited me to call or text him if I need any help moving things along but he also said that he would be escalating my primary issue so they will supposedly get me an SC appointment ASAP.