That’s cool. It would work for the mirror display functionality, but handover is more like CRIU in the sense that it becomes a process on the target host. Moreover headphones are also switching. So it seems a bit more involved than either.
For stateless processes, probably, but there are non-trivial problems reconciling state - think of your IDE / vim along with maybe a debugging session of another process. You need a lot of things in place to enable this use case for productivity goals. This is not an uncommon scenario for the current audience (I use AVP almost exclusively for work and think many users are engineers).
There may be simplifications to this, but I suspect it eventually lands in a distributed system problem involving state and strong consistency semantics. I’ve done this for most of my engineering career and all I can say is that they are fun problems to work on because they are some of the most difficult ones :)