Guess, but GPU drivers have been known to change shaders being sent to the GPU for certain games, to fix things and increase performance, it's possible this could be detected as some kind of cheating by the anti-cheat.
Good guess, but most games don't actually look for that. The closest I've seen is them saving off the final rendered image and checking for wrong information. I think Vindictus was one that did that (learned about that outside the job so I have no issues sharing that.) I believe they mainly used it to detect cosmetic mods that might cut into their profits.
We only really replace shaders to fix issues that the game devs won't fix, and only then when the game isn't updated very often since it has a high chance of breaking our patches. On top of that I don't believe there is a good way to pull the information back from the driver in a reliable way, so it would be very hard to rely on any information that comes back from the driver.
We only really replace shaders to fix issues that the game devs won't fix, and only then when the game isn't updated very often since it has a high chance of breaking our patches. On top of that I don't believe there is a good way to pull the information back from the driver in a reliable way, so it would be very hard to rely on any information that comes back from the driver.