Well I didn't get as much done with this as I'd hoped. The choice of skipping Godot-XR-Tools made the game much smaller, but also meant I didn't have access to a 3D UI/Menu system - as such the room-scanning is best done in the headset and there's no in-game instructions or option to quit.

While I'm publishing versions for all major headsets, it's only going to be interesting to play on the Quest 3, as this is the only one with room-scanning options.