High output jet afterburner? Hardly.
Its just an outdoor gas stove on a medium flame. And most probably on a low pressure regulator which ive only realised myself after recently watching a video showing what
can be achieved with the correct regulator. (i also have the wrong regulator for a decent flame on my outdoor burner)
This video is supposed to be a test between high and low heat. But when BI tells CA he needs more heat and to turn the third ring on, he bottles out. :

edit:
But,, i still dont think the third ring would make a lot of difference. Its all to do with the regulator.