Really? I didn’t know this was possible. In my experience, there aren’t many people on the live servers in Amsterdam region, mostly because there’s never any ATC there …they are all in SoCal or San Fran.
I have no idea how this game is programmed, but a short loading time from region to region, should it be connected, would be acceptable. Say you hop from Heathrow to Köln Bonn. Whenever you leave the UK region for Amsterdam, you could be automatically transferred from one to the next, while the app loads the new region and dumps the old from memory.