I think this is mostly the same issue as https://mods.factorio.com/mod/grogs-quality-hell/discussion/678577ca8a18edf410096a1a but I wanted to create a new issue to make it more clear to newcomers that this mod seems to currently be non-functional.

I got slightly different symptoms than the other thread: for me at a certain point every single building (drills, furnaces, assemblers) stopped producing quality items. I tried jacking up the settings to 3000% quality, and there are still zero quality items being created. I was able to fix the issue temporarily by uninstalling the mod, creating a temporary save file without the mod, then reinstalling the mod and loading the temporary save.

Also it sounds like there's supposed to be a gui of some sort, and I wonder if its absence is related.