Just an idea from the above. I do not have the answer, but question to the experts coming to this thread:
Is it possible to plug the z-wave & zigbee usb sticks onto a Pi 2, and run a Pi OS and the zwaveJS2mqtt / zigbee2mqtt dockers on that Pi 2 box, and setup HA to talk to the zwave2mqtt (on Pi 2) either via websocket or via mqtt?
Probably too much for a beginner like me, but if at all possible, that might help decouple locations of where the HA server is and where the z-wave / zigbee hub is, right?