You can. In the file C:\Users\USER_NAME\AppData\Roaming\Fatshark\Darktide\user_settings.config find line 111 and set vertical_fov to 150 e.g. so it looks like this:
vertical_fov = 150
This leads to a HFOV of 167° as it’s scaled up from vertical FOV.
Small tip: don’t go to 150. It’s soooo much FOV. 
105 seems quite good to me. And: the FOV is not affected while in the Hub but only in the missions.
