Geo-fencing works by the location of your phone (or other geolocated device) to know whether it is “within” or “outside” a predetermined boundary.
My heating works this way (Tado) - When I leave home my heating turns off. When i return it turns back on.
Unfortunately, unless I lived in Buckingham Palace, this would not really work for zone switching for Roon, as geofencing is not able to work to such granular detail like room by room, and would struggle to switch with any accuracy.
That’s what I’m thinking. You take your phone with you when you leave house and it’s easy to figure out whether you’re home or someplace else. With zones inside the house, it’s a totally different problem.
I can think of a better scenario. You wear headphones and a tracker that not only determines your position inside a space, it also tracks your head movements and makes sure the sound comes from the same location in the house. You can configure it to stay put (and behave like there were no walls) or “slide” to a different fixed position when you cross into a different room. We can build that, we have the technology.