This seems to apply to any situation where the player has a large number of input devices.

I have two VKB Gladiator steering wheels, pedals, a gamepad, and an OpenTrack head tracking system. If everything is connected at the same time, the game's FPS can drop by a factor of 4 and there will be constant freezing. Although there are no problems in other games.

Something is wrong with the axis recognition and device polling priorities...

This really pisses me off too. It would be nice if they were at least sorted alphabetically instead of randomly.

I have exactly the same problem. On any map: Everon, Kalguev, Arland. The first launch is fine. Restarting the game causes an endless loading screen. Restarting sometimes solves the problem, but not always. Deleting the save folder is guaranteed to help, but that's not normal.