I don't expect that many trap shooters shoot steel, that is why there is no comment.
He is loading 21g of Red dot with a 7/8 oz pay load, absolutely no way that load could generate any kind of pressure in any 2 3/4" hull.
The question that I posted to Wade was whether or not Steel in a WW aa12 wad was ok, I have never loaded steel, but have shot a gazillion AA hulls loaded with 21g of Red Dot with 1 1/8 oz of 9, 8, and 7 1/2's for skeet leagues.
I am familiar with most of those hulls he used, they all have similar case capacities and that load is no where near max in any of them.
I have my favorites of those hulls. I was at That same shoot they were at. We were there also going through the dumpsters, I picked up Green Remington STS, gold Remington Premiere, and Black Remington Club. We got about a 55 gallon drum of clean Fiocchhi Hulls that are very good for 1 3/8 oz to 1 1/2 oz lead loads.
I did not see Wade do anything dangerous, but the practice of not going by a single load recipe out of a loading manual is not politically correct. Wade is far from a beginner reloading. The load that he used is safe in all of those hulls, not to worry, although some of the crimps were not good. I would go to a Fed PC3 on some of those hulls where the crimp was starting to cave in a little, and a Remington RXP wad on the ones where the space was making the crimp pooch out a little.
Down where Wade lives, there is a tremendous swamp and Wood Ducks are thick as fleas down there, which is why I think he has steel shot on hand. There is not one thing dangerous on mixing shot sizes, he probably got a deal on it for that very reason.
I am concerned about shooting steel shot in Win AA wads, but the size shot he is shooting is very tiny. I would trust Wade's judgment, he is no dummy and takes care of his guns. I suspect that small size steel shot is very different than large size steel shot when it comes to the demands on the thickness of a wad.