I've tried a few things but not really found an ideal solution.
The problem mainly seems to be that he places new meshes directly on top of (or too close to) existing ones, creating a conflict.
At Silverstone, for example, new adboards are put directly in front of the existing tyre walls, and a lot of them flicker until you get close. The flickering can be stopped by hiding the tyre wall behind the adboard, which looks OK from the driver's perspective but can look odd from replay angles.
I don't know whether Pyyer's setup (hardware or display/AC video settings/CSP) means that he never sees any z-fighting, or whether he just chooses to ignore it, but for me it's incredibly distracting and often a deal-breaker.
It's a real shame because the extensions in principle are a good idea and are generally well executed, apart from all the flickering adboards.
I've messaged him before about this at RD but didn't get a response.