This is a simple mod that allows you to customize the game's field of view.
Just put FovAdjust.dll in BepInEx/plugins/. After installing the mod and running the game, it will generate a config file in BepInEx/config/. You can adjust the FOV from there. You will need to restart the game for changes to take place.
There are two chat commands you can use; /fov and /toggleVisor.
/fov # will change your FOV to whatever you set as # (clamped between 66 and 130).
/toggleVisor will toggle the visibility of the first person visor.
Note: Using chat commands will not change your config file, you still need to edit that to change the default values.
/fov and /toggleVisor.