Wrapping up the facts to sort things out before I post a Confirmed Solution... Sorry if it's a *bit* messy atm, and feel free to post any questions/comments.
Hopefully people looking for info on SH5 will find some answers here.
-Resolution support:
All resolutions up to 2560x1600 are supported natively.
You can also edit the [VIDEO] section of My DocumentsSH5datacfgmain.cfg
Minimum resolution is 1024x720, any custom resolution of height<720 or width<1024 will be 'corrected' automatically.
All ARs are supported including 16:10, 15:9, 16:9 and pretty much everything else.
-Two-folded widescreen support:
Free cam (external view) & guns: Vert-
4:3
16:10
16:9
First-person view: Hor+/Vert+
4:3
16:10
16:9
-Stuff that can be modded: (I still have to try a couple things, so I'll post more details later.)
I have no idea how to mod the first-person view. :(
However a couple other FOV values can be edited in
Silent 3ditor, so as to make the free cam & gunner view Hor+.
Open C:UbisoftSilent Hunter 5dataLibrarycameras.cam and look for the 'AngularAngle' value under CameraParams at index #19, 183 & 195.
16:9, free cam, AngularAngle = 91
-Multi-monitor gaming is unsupported.
The game will run at any multi-mon res, but the broken first-person view renders the game unplayable.
The Hor+/Vert+ FOV results in increasingly distorted graphics beyond a 16:9 AR. The viewport starts to collapse at ARs > 3:1, and the whole 3D scene turns to solid black at actual Surround resolutions.
2800x900, first-person view
2900x900, first-person view
4320x900, first-person view
The Free cam is just Vert-, though.
4320x900, free cam