I experimented with uGridToLoad=7, really liked it but the game became unstable enough that I ended up reverting back to default. I followed through with the tweaker guides and I'm playing my savegame fine now except all my load screens show discolored, slightly pinkish, 3D objects. See attached picture for one example.
I've already checked the cache integrity through Steam and this is the only visible artifact/problem. Perhaps I should just count my blessing but if anyone else has or had this problem and found a way to fix it, could you reply to this thread?

It works.