28kW of dissipation is pretty solid, though obviously is irrelevant during a short burst with hundreds of watts of heat generated. I guess the frame itself act as the fallback heatsink for storing excess heat in these scenarios? Because by my math, a modest 100kg heatsink (no idea if that's reasonable) would reach 270°C in only around 45 secondw if it's trying to handle 250kW+ of heat transfer (270C is roughly the max differential for heat pipes,liquid cooling might be significantly lower limit). And obviously the batteries can't handle 270C.