Example: https://www.curseforge.com/minecraft/texture-packs/shimmer

It's especially noticable with this resource pack https://www.planetminecraft.com/texture-pack/shiny-ores/
The vanilla shader just does not work.

This is impossible to fix, even on the Fabric version.

I guess that no more needed since you ported oculus. Free to you to close it or fix it. But more things could be done with oculus rather than vanilla shader feature.

sounds exhaustively