Baseline (Widescreen) Solution & Issues
It was difficult to get perfectly consistent screenshots, manually setting the heights. The screenshots are taken by going to the lowest camera setting, and then pulling back five "clicks" of the mouse wheel. I could get consistent shots between 4:3, 16:10, 16:9 and 4k, as they were all taken during the same game session.
The 21:9 and Eyefinity shots had to be recreated in different sessions, as the game resets the camera height to a default on each game load. Unfortunately "five clicks" isn't simply "five clicks", as the game recognizes velocity of the mouse wheel. The shots are very close, but not completely identical.
Ultra/Super-Wide (21:9/32:9) Specific Solution & Issues
Eyefinity / Surround Specific Solution & Issues
The game HUD and menus disappear at a certain camera height in multi-monitor. This can be an issue when changing screen resolutions. The game will initially default to single screen res (i.e., 1920x1080) on multi-monitor. When changing the resolution to 5760x1080, I initially couldn't confirm the change as the confirmation screen didn't show. Lowering the camera height at 1920x1080, and then changing resolution, allowed me to confirm 5760x1080.
4k UHD Specific Solution & Issues