I've updated the
Confirmed Solution, let me know if there's sth unclear.
Further details:
You can mod a number of other camera settings to your liking, see config.cfg for a list of all variables and their default value.
As you may or may not have noticed, this is not a pixel-perfect Hor+ solution as far as the main game window is concerned: it is "vastly Hor+/slightly Vert-" although it's hard to notice in non-surround resolutions. The PIP camera (bottom right) on the other hand is strictly Hor+.
Why is that ?
It seems the default FOV values apply to the PIP camera, which in turn affects the main camera's behavior. However the PIP's frame is a square (i.e it's 1:1 at 4:3 resolutions) that stretches in wider aspect ratios. It's never as wide as the main game window, so the correct FOV values for MAINCAM should be a tad higher than those for PIPCAM.
Resolution AR // PIP AR
1.33:1 // 1:1
4.8:1 // 3.7:1
1.77:1 // 1.38:1
Someone keen on math could easily calculate the right FOV values for the main cam, so that it is as strictly Hor+ as the PIP cam. Seeing how easy it is to mod the FOV to any value, and how satisfyingly Hor+ the game is even in Wide TripleHead, I hereby confess that I won't bother.
Did anybody really read through all of this ? You have my thanks.