Try to change the resolution in the ini file. And with the 3renders line code it should span the correct resolution across all three. Do it just like how you would change the resolutions in IL2 that weren't supported default. And get track IR rather than spend 8 bagillion dollars on 3 monitors.
Mind you, I'm guessing. I'm in US and I'm one of the chaps that's going to pretend the game doesn't exist until APRIL 19. sheesh.