Using Simlink instead of FSUIPC (Radar Contact used FSUIPC, Pro-ATC/x uses Simlink) would let you actually inject menus into FS, vastly improving the user's experience, simplifying it, etc.
That way, the ATC interaction could be menu driven, in addition to hotkeys, simplified hotkeys, like Ctrl-1, 2, etc. Yes, those are assigned to the radio volume controls, but that's what deleting/changing assignments is all about. Also, FSUIPC is considered slow af, compared to Simlink. That was Radar Contact's main problem. Running menus and the FSUIPC message box was slower than it needed to be.