It would be nice if there was a way to allow a Flatpak to login to the desktop. I think this could be a major security issue but theoretically there could be some sort of system to allow a remote access tool to start a desktop session on successful login. Right now it seems like all of the remote desktop stuff is limited and desktop specific.
Ideally there should be a common way for apps like xrdp and Sunshine to start and control a desktop session without major work arounds or root. I get that desktops like KDE and Gnome have there own things but ideally it should be standardized so that any app can manage remote desktop. There are obvious security considerations since a remote access manager app would have full control of the system. I just think there needs to be some solution since remote access is a common use case.