Very impressive procedure here.
One thing, I'm not clear on though. Am I to understand that your cartridge is primed and charged, then the wad, shot cup, and shot are loaded. Then, you put heat or flame on the end of the petal ends, while the round is "live"?
If so, then I would be a bit concerned about bringing a loaded cartridge near a heat source. Am I being a nervous Nellie here on this point?