@Frayedknot If your device is a P3a, several of us have noticed this. It's something to do with UT, not the carrier. I haven't had time to troubleshoot it, so haven't filed a bug report for it yet.
@planejoe great stuff 🙂
I cannot comment much about the partition layout, some looks legacy in link with the android container i'd guess... though not required on PinePhone. If you check the multi image, Ubuntu Touch run from a single btrfs partition if i'm not wrong: https://xnux.eu/p-boot-demo/