Resolution:
Set a know Resolution (like 720p or 1080p) so you find all the spots in the file.
Go into the file "%LOCALAPPDATA%\the_citadel\Saved\Config/WindowsNoEditor/GameUserSettings.ini" and open it with a Text Editor.
Change all lines to your needed Resolution.

FOV:
Change the Graphic Settings to your liking.
Go into the file "%LOCALAPPDATA%\the_citadel\Saved\Config\SaveGames\sav_graphic.sav" and open it with a HEX-Editor.
At the line "0000:0520" at the marked point below:
00 00 00 00 00 00 00 00 XX00 00 00 00 13 00 00 00

You can change the FOV by change the value at the marked point with the XX. Around 64 is 100FOV and 99 is around 156FOV. That's the Limit from my testing what the game code can read. around 94 (146FOV) is the sweet spot for ultrawide.

Also replace the Resolution you can see in the text view in the Hex editor to your custom one.

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Make Backups so you don’t lose your setting accidentally after opening the Menus and pressing Apply by accident.
Works really good from my Testing

More Aspect Ratio related fixes (By nightc0re):
https://steamproxy-script.pipiskins.com/sharedfiles/filedetails/?id=3033656931

Helped a lot:
https://steamproxy-script.pipiskins.com/app/1378290/discussions/0/2805133852509601652/