Would getting a metal or ceramic desk act as a giant heatsink?

Yes I know that using a cooling pad is the best option for me. But I'm just asking a theoretical question because my current wooden desk is contributing to the thermal throttling. Wood is a poor conductor but an excellent insulator of heat, and the air between the laptop and the desk will constantly be heated up. I did re-apply thermal paste, clean out the dust, and undervolt my CPU already but under heavy load for CPU bound games, it has limited effectiveness. Underclocking my CPU had no improvement on thermals neither did limiting the max CPU state in power plan settings (lowering power plan lowers fps too).