I'm not curious at all. As a control for a mod 2.5 years ago I tested an unmodded sk68 clone once, XR-E on a 14500 IMR, 1.5A, hollow pill, thin alu ledboard, no thermal paste just press-fit with a plastic washer, and it just worked fine for a full battery drain without cooling. If more amps are used in a mod just change to a copper board (twice as thick, twice the conductivity so 4 times the heat drain capacity) and you'll be fine again up to 6 amps, in that same hollow pill.