Well, it seems like I can play longer now, however, it still doesn't work correctly. After a random amount of time on a 100% clean, no mod install, it still shuts down.
Not sure what the real problem is here. There is no fps loss, there …
I've done everything but unsubscribe from all my mods, which I've done just now. I'll post after I see how that plus following all the steps on your guide goes.