Thanks for the detail write-up Hedda. A month ago a had a firmware corruption on the CC1352. I had to spend quite sometimes troubleshooting it before finally having to re-flash the firmware. At that point I decided to order the Sonoff Zigbee 3.0 USB Dongle Plus. I just successfully integrated it with zigbee2mqtt, which didn’t require re-pairing.
I used the cc2538-bsl tool to re-flash the firmware, and the instruction at zigbee2mqtt (primarily to change the IEEE address on the Sonoff stick). After that, zigbee2mqtt was able to pick up the new stick and all existing devices.
If anyone is looking at buying, currently Sonoff is having some discount on this stick (good till Dec 31).