The game does not allow to select 21:9 or wider resolutions, but forcing your resolution is easy via the config file.
In the config folder, simply edit GameUserSettings.ini and modify the values of ResolutionSizeX and ResolutionSizeY.
This way the new resolution will even appear in the game and not be affected by applying other options like the FPS caps.
The outcome is hor+ gameplay but pillarboxed cutscenes and dialogue. Some of the cutscenes simply do not have enough of the level width to show, so the developers' decision makes sense at those. Others would be fine at 21:9.
I've been trying to fix them for perfect vertical FOV for over 12 in-game hours now, and yet there is still no luck in finding a way to not have the FOV compensation after removing the black bars affect the rest of the game. As in Fallen Order, the gameplay FOV is already good and overcompensation is unnecessary. My goal is to code in a conditional check as before. But that takes a condition!