I'm seeing stall medium between the parts as the problem, not just the direct thermal transfer in air. Air will always be moving, although very little, when temperature differences are present in a system. Still, I'm not saying it's a bad idea, just that, at least for me, the controlled enough environment for credible measurements of the heat spread to be taken are quite hard to achieve unless the difference is really drastic, which I doubt.
Sure, why not? It still sounds like one will be left with a back problem and a mess of silicon paste but I'd be happy to be proven wrong!