@feld programs want regular $HOME rather arbitrarily. Not sure if a virtual filesystem can reply with "just hold on", while asking the user if it is ok. (think not?)
It might be good if file-selection browsers was an intermediary, if that intermediary is trusted, you can know the users asked to access to that file. Avoiding the whole prompt thing..
Also, like X and (slightly less so?)Wayland might allow too much too. @ryan_harg @fasnix @yuki2501