We always try to inform game devs about correctness issues, but generally we can push out a driver fix before the devs can fix things on their side, so that pretty much always happens. Many things can be fixed quickly by app profile (detecting executable name). And we have a pretty good relationship with most game devs and usually get some feedback. Of course, we don't have infinite resources, so bigger game devs get more attention to tiny ones.

I'm not sure what fraction of devs actually fix things on their side, though. Once there's a driver workaround, and we've informed the devs, it's off our plate.

Performance is more of a gray area. We contact devs if there's something we can't work around, of course. And if there's something truly breaking. But for things that aren't exactly bugs, just things that could be improved, and we can improve on our own... well, we'll probably keep that for the competitive advantage.