Yup, powder burns are to be expected when you are close to the point of exit. I looked at your videos and my conclusion is the .44 would have a much larger cylinder gap and barrel flash than my .38 does.
Quite a few years ago, I intentionally fired my Chief Special while my hand was holding it under my jacket. I pulled it out of my shoulder holster and point shot the target through the side of my jacket. I was wearing a cotton shirt and a Levi jacket.
As expected, it singed the hairs on my fingers and left a powder burn on my shirt and the jacket BUT I had not lost my night vision which was the intention of the test.
I think I was firing Winchester or Federal loads which I had tested for the smallest night vision ruining gap flash. I recall that Remingtons would absolutely blind you for ten minutes when it was pitch black outside. Remingtons had a monstrous bright white flash as if someone was using a flash camera. Winchester had the orangest flash of the loads I tested which allowed your night vision to recover faster.
I think it’s chamber pressure that makes the barrel gap blast more destructive. I think I read about a guy shooting a S&W500 magnum a few years ago who had his thumb near the gap and the blast severed his thumb. He was holding it like a rifle with his left hand under the cylinder/barrel.