Unfortunately, 21:9 support for Before the Storm never came out, and all the existing patches for the game seem to break online support. So I created a non-intrusive plugin that utilises BepinEx to add your current monitor's full resolution to the game if it isn't already there. And dynamically sets the aspect ratio to accommodate. This means any combination of aspect ratios is supported including 16:10, 21:9, and more.

Also now lets you limit the framerate to your monitor framerates.