https://www.protondb.com/help/improving-performance

So I stumbled upon these tips and I'm not sure how relevant they might be or how old the article is. I guess what I want to know is, how do you use these environment variables:

__GL_THREADED_OPTIMIZATION=1 for OpenGL games
__GL_SHADER_DISK_CACHE=1 to create a shader cache for a game
__GL_SHADER_DISK_CACHE_PATH=/path/to/location to set the location for the shader cache.

How do I add these variables to my proton prefix? At least that's what I think I am supposed to be doing.