Have you tried the triplemonitor.fx shader?

Because there is no triple screen support in this game I tried this shader in Reshade.

I have a 32in triple setting, and my shader values are:

angle=-3.0

curve=2.0

zoom=1.0

Still using the default 48deg FOV in the cockpit view

It is not perfect but better than the very stretched picture without the shader.

Tell me if you've found better settings, thanks.