This was something I didn't expect, because the contents of the DLC has been hidden to users (and it still is) - but it's been affecting everybody's main game files - with the exception of saved games (since those are saved to the Steam Cloud now).

I was assigning the DLC package to the main game - but because the DLC hasn't been released yet, the contents of that remain hidden to users (so in other words, 0MB). I had set the actual package of the DLC in a hidden branch, but I also linked to the main depot of the game (that was already released) - so had that effect. Nothing in the game's files!

It only affected the main game files because it was a child of the main game. (In terms of what gets installed, the DLC package is bundled with the main game).
I've removed that for now until release of the DLC.

I really started to panic, but I'm glad I fixed it. More importantly, I'm glad people brought it to my attention! While I have another user to test installation, I have no other PC - so you can imagine it can be misleading for me.

I've added a new feature, the script is courtesy of Zeus81, and it adds more options to play around with the screen size.
You still can't manually change resoultion and resize the game window (it isn't possible with the software), but by using F10 - you can adjust the screen ratio. That should give you some breathing room for when you want to look at the guide while playing the game or anything else.

Thanks,
Harry