I looked at Pilot2ATC and decided to just stick with the default ATC.
The default gets the job done for basic VFR and IFR flight in the simplest way possible.
For IFR, if you use the main world map to enter your flight plan sans approach, the in game ATC will do a decent job of assigning an approach once you enter destination airspace which is one realistic element I like. Where it falls down is in altitude assignments where it may have you too high on approach or hitting terrain. You just need to use intelligent disobedience and plan your descent appropriately, ignoring ATC if they don’t agree with what you’re doing.
The best part of the default ATC is the UI is simple… number keys choose your request/response, and it automatically changes radio frequency so you don’t need to bother with that. Perfect.
The problem with Pilot2ATC is it’s way more than what you need which adds clutter and complexity to the UI.