Something like 99% of recent, sensational, and high power XH reports show the the output power totally in step with the input power.
I find that suspicious, quite frankly. I would expect bursts, or out-of-step heat-input relationships.
But no matter how the Kanthal gets overheated, once it melts, that's pretty much the end of the experiment. One might also consider that the thermal resistance of alumina means that bursts of internal heat may melt the internal alumina (and/or anything else inside) before the heat can be effectively conducted to the surface. Once beyond the Critical Radius, the alumina is insulation.
yes, I agree, it remains speculative however what incredible results do you refer to?
Apart incredible little oversold XH from last ICCF, i don't know any ?
Also, I agree with your mistrust about XH signal found too perfect.