It just occurred to me quite randomly that I've seen Bruce Lamont three times - once as a solo act, once with Yakuza and once with Bloodiest. Don't know if that counts or not.
Come to think of it, I've also seen Erik Wunder twice - once with Man's Gin and once with Cobalt. That probably doesn't count, but both performances were incredible, so fuck it - I'm bringing it up.
Also saw Jackie Gratz twice - once with Grayceon and then twenty minutes later with Giant Squid.
Ditto the above comments for that one, too.