2 z-wave controllers setup

  1. POE controller + Z-Wave JS UI (connecting to controller via TCP serial) running on a host somewhere
  2. An SBC (e.g. raspberry pi) or mini-pc using a USB controller and running Z-Wave JS UI

In both cases, a second Z-Wave integration connects to Z-Wave JS UI.

It may not be common, but there are a non-zero number of users doing so.

I also do this for testing purposes, e.g. one network is the normal production one, 2 or 3 for testing.