So to follow up on this... A different installer came by a week later to install new meters. He had no idea what the condition of the site was prior to getting here. He called his supervisor to figure out what he should do, and left 15 minutes later. It didn't make sense for him to install the meters when the batteries still needed to be relocated.
A few days later, another installer team came by to relocate the batteries. These guys were also surprised by the state of things, and they too needed to call their supervisor. While they were on site they took measurements and drew up a plan to relocate the electrical panels higher up on the wall, so that we could fit the Powerwalls below them. I was ecstatic -- although the installation footprint would still be much larger than originally expected, at least it could be contained to a single garage wall. The installers told me they'd have to come back on a different day with additional help, because this was a job for more than two people. They took a picture of the plan they had drawn up on paper, sent it to their supervisor, and left the paper with me.
On our next appointment, only two installers showed up and once again, a different group of guys than the last. They walked me through how they were going to relocate the batteries, asking which additional walls they should use for the Powerwalls, where to run additional conduit, etc. Once more, these installers came in to the job site completely blind: they had heard nothing of the updated installation plan. Thankfully the previous guys left me with a hard copy. I shared it with the new team and they objected at first, which is understable since they were completely blindsided by it. That being said, the alternative they proposed was not acceptable to me and I was considering canceling the project. After spending some time on the phone with their supervisor, they relented. They let me know this would now become a two day job and that we'd be without power for the first day. My partner and I had planned for neither of these things, but we dealt with the inconveniences in order to see the project finally completed.
To their credit, the installers did a good job and I'm happy with the final result. But this has been the worst installation experience I have ever had. I'm frankly embarrassed for Tesla Energy that this is how they conduct their business, and how they treat their installer teams.
The system was turned on yesterday and so far, so good. It's just been a long 6+ months to get here