Can you test this issue on Yosemite (10.10) and see if it occurs there? It's possible Apple may have skipped Mavericks for the fix, and reintroduced it into Yosemite. I noticed a few fixes in Yosemite that brought certain OS aspects back to pre-10.9 (as in, back to ML) for fixes. (Time Machine, finally sticking to outside-/~ folders, like ML, hopefully staying that way 'til final release, I'm looking at you.)
I wish this was true. I reinstalled or downgraded to my previous OS's again since I needed to do some work on my MBP. Well, I wanted to see if my Mid-2010 MBP could do the work, anyway. Suffice to say, OS X 10.8.5, OS X 10.7.5 and OS X 10.6.8 exhibits the same GPU-related Kernel Panic for my machine.
Damn it, Apple!
I was secretly hoping it was the OS or something with software. But, now I'm beginning to lean more on hardware. Although, KP's are software-related. So, you could still be right that there is a hardware-software issue happening with some Mid-2010 MBP's. Maybe, it's like deep software or firmware or bios that has something to do with Video. Like the Apple Mux Controller. I don't know what it is. But it's in all the console message logs.
I think I am going to do that fix thing I saw in one of the forums that makes the GPU use the main RAM or something and see if that does something.
I am really running out of options. I could reserve a Genius Bar appointment again and try to speak to one of the managers about the Mid-2010 MBP issue and see if they'll soften up and take mine for a free LB swap. But, for some reason, I don't see them budging. And, they shouldn't. Apple MBP owners with legitmate issues should not have to rely on luck in finding a really nice Apple Store Manager or using the power of insistence and mind-control jedi tricks to convince them for what should be a free service since they already admitted to the "Latent Manufacturing Defect" thing.
Whatever.