For visionOS, is there an API or function i can use to determine if the user has a Persona set for video calls? If not, is there any way i can attempt to determine "something" is available?
On visionOS, detect if a Persona was set by the user
Indeed there is: https://developer.apple.com/documentation/groupactivities/systemcoordinator/participantstate
Check the ParticipantState for isSpatial after you setup and initialize your GroupActivity.
When you say "GroupActivity". what do you mean specifically? In my case, i have developed a video calling app (not Facetime), and for my app, i went to verify if the user (the caller) has setup a Persona and advise them to do so if they haven't, otherwise, they will be sending black (RBG 0, 0 ,0). So, being I am not using SharePlay, will that participantstate function work?