Baseline (Widescreen) Solution & Issues
For cut scenes, you'll need to replace the original "Assembly.CSharp.dll" with the fixed one in the files available from the PC Gaming Wiki Community Files (search there). or download dnSpy, then look for CutsceneCameraAspectRatio and replace the 16:9 float at the first "num" parameter with "(float)Screen.width / (float)Screen.height" and save it, then the cut-scenes will play without the borders.
Ultra/Super-Wide (21:9/32:9) Specific Solution & Issues
Some elements get misplaced on wider resolutions such as the logo which may have some parts trimmed off.
Eyefinity / Surround Specific Solution & Issues
4k UHD Specific Solution & Issues