Ha ha I see more than a few of us have developed the "flick of the wrist". I don't imagine it's a real big deal how the prime lies in the pan, but I just like to know everything is perfect.
I don't hunt from a tree stand, but I always load at home, and still would if I did. When I load a rifle up that I'll be hunting with for days or weeks, I want to do it in a well lit, dry place, with no room for errors. That don't mean I can't load my rifles in the dark...just like to be sure everything is perfect again.
When transporting Bess, which has a fairly deep touch hole, I've always kept a feather in the touch hole until I'm ready to prime. With Rosie (the Jaeger) and her high-tech touch-hole liner, the powder lies RIGHT THERE, I mean you can see it laying against the hole, so I cant' really cram a feather in there, or toothpick as that would just crunch it up...don't really want to do that, so I'll have to come up with a new plan for her. Maybe just wad up a dry-patch next to the touch hole and close the frizzen over it.
Anyhow, I don't really see a safety issue with a loaded but unprimed flinter, with the frizzen open, cock down, and something plugging the touchhole.
Rat