FSR and lower settings (texture resolution and shaders in particular) are your friend. Also Gamemode to reduce background load from other processes, but Bazzite already takes care of that I assume.

Other than that there's hardly anything you can do except limit your gaming to any game with a mininum requirement of <=4gb VRAM. In some special cases there might be mods available that pull down the graphics harshly beyond what the game intended (I know such mods from e.g. NieR:Automata), but that's pretty much the limit of possibilities for the end-user.

In emulators there sometimes are settings letting you adjust the texture sizes, internal resolution and alike, those are definitely most interesting if some game lags on your machine due to VRAM.