Reenactment powder is pretty much designed for blanks only. There is none of the rigorous QC on higher grades of powder to ensure consistency. It's still real black powder, but think of it as the cheapest, lowest quality they can make and still call it "black powder". For live fire, absolutely not the best. Can you live fire with it? Yes, but don't expect to even be in the area code for accuracy and consistency, both of which reenactors don't care much about. They want cheap to make boom smoke.
Skirmish powder? Sounds like a marketing ploy. We skirmishers in the N-SSA care about accuracy and quality so many of us use nothing but Swiss or Old E or a similar grade of quality target shooting powder. Some use Scheutzen or regular Goex, but that's often only for smoothbores. Once someone gets bitten by the live fire competition bug with Civil War arms, they're not going to be wanting to handicap themselves on the range by going cheap on the powder. Like we used to say when building race cars- "speed costs money, how fast do you want to go?"
