Home Assistant Connect AUX-2 gives your old speakers and TVs a second life for $69
(www.androidauthority.com)
The product announcement explains that they're essentially doing USB-over-IP to support the Z-Wave adapter, but they can't get Thread to work that way. The timing isn't precise enough, or somesuch. They will need to write new firmware to turn the AUX-2 itself into a Thread router to make it work.