Scratch my last reply about refresh rates. I went back through my notes from when I fought this same problem on my own machine, and the real answer turns out to be much simpler.
The game's 3D Resolution dropdown does nothing at all. On my machine my selection was never even written to the settings file. The sharp picture comes entirely from the dgVoodoo.conf file the fix installs in the game folder. There are two important lines in it, a scaling mode that keeps the aspect ratio and a forced maximum rendering resolution. With those two lines in place the game can ask for whatever mode it likes and you still get a full resolution picture. Without them you get exactly what your screenshots show, the game's real low resolution output sitting unscaled inside a black border.
I think yours lost those lines. The dgVoodoo control panel you were experimenting with rewrites that config file with plain defaults if it is ever pointed at the game folder and Apply is pressed. My installer created the file when it was missing but never checked the contents of an existing one, so the repair screen showed all green while the config was actually wrong. Your screenshots are what exposed that gap.
I have just released v1.7.1 which closes it. So here is what I would do. Put your NVIDIA scaling settings back to how they originally were, delete your old BOB2-Win11-Fix folder, extract v1.7.1 next to Bob.exe and run Install and repair once. It will spot and restore the config by itself. Then fly. I would expect the borders gone and the picture sharp at your monitor's full resolution.
If it somehow still misbehaves, the refresh rate test from my earlier post is the next thing to try, but I do not think we will need it. Thanks for the screenshots, they hopefully we cracked this.
