I doubt there's much difference. Just implementation details. The retroarch spec is a lot to code if you're just looking for one or two shaders. Also FYI: your

I doubt there's much difference. Just implementation details. The retroarch spec is a lot to code if you're just looking for one or two shaders. Also FYI: your link features a lot of shaders using the megabezel presets, which are extremely unoptimized. The koko-aio bezels in the same slang-shaders repository can do the same effects, but with much better performance.