Fixed it.

I'm not happy about this... I was messing around with render settings yesterday. Enabled CPU fallback just to see what it would do. If it would help my scenes... Forgot to disable it. That was causing the render crashing. I reinstalled windows for nothing.

That being said, I do now have a clean install of windows, so that's a plus... But I have to go create a new AI workflow in ComfyUI... That'll take hours. And I still need to clear Daz Studio of the 10's of thousands of Morphs I have so that scenes don't crash when I try to pose a character...

But AT LEAST, my PC isn't broken. And now it's completely fresh.