Thanks (can’t comment yet; have requested an account)!
Additional data point: from this thread it sounds like sunfish on dev/T updates without problems. (Unsure if this applies to bramble as well. Would love to test if I can reproduce on my sunfish but the upgrade path description here is a bit too fuzzy for me.) I’ve had a glance at adb logcat during the update but haven’t spotted anything that seemed particularly helpful (to my untrained eye). Are there any other places I should/could look at?