I'm advocating for density and buoyancy, and where did I say heat doesn't rise?

It doesn't! Technically...

Heat is actually radiation, so heat technically radiates.

Upon absorption of that radiation, the gas expands which decreases its density which causes the phenomenon of convection (aka, "heat rises" - which it ("heat" actually referring to the hot gas, NOT heat) doesn't, it goes all directions)

Way to stay frosty, brother or sister!