Unfortunately, until gaming becomes possible on Qubes, I can’t really do a non-multiboot setup. Also, I doubt coreboot is compatible with modern (12th gen Intel CPU-supporting) chipsets/motherboards, because I only see pretty old (7th gen) motherboards on their compatibility list: Mainboard-specific documentation — coreboot 24.02-112-gec7b480760 documentation
I also heard that coreboot’s performance isn’t as good as stock BIOS because it isn’t as aggressive as stock BIOS, and performance is important to me.