I dont know what I did, but I am a miracle worker. 
 
With Adaptive Vsync, 6 pre-rendered frames, and a few other Nvidia Inspector tweaks my old rig is running this game at 45-60fps (Low 30s briefly when nearing new load zones) with all of the settings on Ultra but shadows on Medium.
 
Smooth as butter. This game's performance makes no sense. My rig shouldnt be getting anything near that imo...but maybe Im wrong. 

The settings do tax my system but I can play with 30fps constant. Game looks and runs just fine. 
 
If I turn off frame limiters then the game runs from anywhere between 30-60 which is annoying to play with such variation. 
 
My problem is, that any config edits I make dont seem to do what they are supposed to do. If I change a value, then when I load the game up it just resets the value. I've never had a game do that before. Ive had games run terribly, crash, and just about everything else but never ignore what changes i made.

When I make the ini file read only, it sets all my other settings to low.