I'd like the choice of being able to stream either an egocentric position (what I see) or some kind of third-party position where people can enjoy my cool avatar.

If it was something like Horizon Worlds I'd very much want to be able to participate or at least spectate with a desktop computer. Decentraland shows that you can make a perfectly usable interface for this.

I'm having fun placing "Holograms" with my Hololens 1, I'd like some library that would let me make objects I could see with my hololens or see superimposed on the camera image on a phone or tbalet.