Can't get my ZBT-1 working again after multiprotocol was deprecated.

[left snow]

Like many people, my zigbee and thread devices stopped working a couple weeks ago, and I've been trying and failing to ZBT-1 back online.
I didn't document every step, but I've tried disabling multiprotocol the official way which didn't work, web flashing, the add-on flasher. I've finally managed to reconfigure it in HA and it appears to have correctly installed EmberZNet Zigbee 7.4.4.3, but now I'm getting an 'unknown error' when trying to set up ZHA again. I'm also noticing that it appears to be mounted to ttyUSB0 instead of a serial port. Maybe thats the problem? I'm a little lost at this point. Running HA as a VM on a Synology. Everything worked great until the multiprotocal was suddenly disabled.