Convenience Update that adds keyboard shortcuts:
Control + Home -> Toggle active
Control + left/right -> change UI scale
Control + up/down -> change FoV (Field of View)
Control + page up -> set 3840x2160 resolution
Control + page down -> set 1920x1080 resolution
Users of older Versions - remember to update your session Plugin defaults to V4.
5K or higher resolution monitor?
The page up 3840x2160 resolution is hardcoded, but can be modified easily.
Use 7zip to extract the source code, edit the following code to your desired resolution, then zip it back into the var-file.
C#:
if (Input.GetKeyDown("page up"))
{
PickRes("3840x2160"); // <- just change this to your resolution
ApplyRes();
}