I don't know what "advanced materials" are, but ALL other sceneries from other major companies for P3D don't do this and these sceneries are as good as FSDT KLAX.
They just got lucky they never used a material settings combination that the tweaked shaders didn't ruin, but of course we use 100% fully documented SDK materials so, it's those that makes tweaker shaders that should ensure they don't wreak havoc with stuff made following standards.
Also, it's not true tweaked shaders cause problems to FSDT KLAX only. Airport sceneries are usually simpler (whether they look good or not, is highly subjective, I think most of them looks very flat, but that's just me), but if you read on many airplane developers forums, they are almost all against shaders tweaks, because they spend to much time trying to perfect how the aircraft will look like, only to find users with totally wonky colors, because of tweaked shaders, that's because advanced material settings (but still 100% SDK compatible) are more commonly used in airplanes.
See this post by PMDG, they won't even provide support to those using tweaked shaders:
https://forum.pmdg.com/forum/main-forum/general-discussion-news-and-announcements/5957-11mar19-shader-mods-if-you-are-having-trouble-with-artifacts-after-our-747-pbr-update-you-need-to-read-thisNow go there, try to say there are other airplanes out there that looks as good as theirs and don't show any issues with tweaked shaders, and see their reaction...