Graphics fidelity "presets" - how?

I have a plugin that detects what hardware the game is running on.
How do I tie together culling distance, texture mip level, LOD level, some cvars that control volumetric fog fidelity to graphics settings “presets”?
I’d like to apply “presets” (probably in the Game Instance) that change aforementioned settings, based on what GPU/CPU is, automatically. Thanks