First, did you actually watch the entire video? Out of the 4 pistols he was using for testing, only one had a frame-mounted comp on it. Saying that "in most of it he used a frame mounted comp" is completely false.
Second, the pistol that he said he thought was "overwhelmed" by the Win 115gr and the 95gr "wildcat" hand load was not the frame-mounted option at all. It was on the shorter-barreled (3.75") Shadow Systems CR920P. And he elaborates that this isn't simply because of factory ammo (the 95gr load isn't actually "factory" at all), but that because of the shorter barrel, a fair bit of the powder is still burning when it hits the comp, and is not converted to gas yet. And what he actually said was, "both of those loads overwhelmed the little compensator, in terms of getting the most out of it." Your simplification of what he said is not accurate.
He also states at 11:04 that the AXG Legion combined with the 95gr load felt like the comp was "overwhelmed." Again - that is not a "standard load" but a very high pressure handload combined with a 3.1" barrel. So - that's two different guns with sub-4" barrels that didn't perform as well with higher pressure loads, which was not an issue with the other pistols that had longer barrels, and esp. in the case of the Staccato. He explains that it wasn't actually because of "gas" at all, but because less of the powder has yet converted to gas in the shorter barrels. That seems like useful info to share, dontcha think?
As for the overall results of his testing - he's literally showing the measured angle of climb with each load and each pistol, with consistent methodology. I don't know how those observable effects are debatable, unless you want to debate geometry.
And I think we all know that it is gas that makes a comp work. There is not a single thing stated in that vid that suggests otherwise.