My remarks obviously said more about me than banjo flatpicking.My musical obsession is American old time music. In the venues I am most familiar with (Clifftop, Mt. Airy, etc.) flat picking a true five string (not a banjo uke, not a banjo guitar, not a banjo mandolin, whatever) is extremely rare. I cannot recall having experienced the pleasure at any such event. My guess is that if your band featured a flat picking banjo player you'd be placed in the non-trad band contest at Clifftop as opposed to the trad band contest.
This should not be viewed as a comment on the aesthetics of flat picking a five string. I assume it can be quite delightful. It's just the way life is in my world.
I am occasionally found at the odd bluegrass festival. The rules of appropriate banjo style are definitely much stricter than at old time events. Never heard a banjo flat picker there. Never expect to.
Come to think of it, I haven't run into such a style at the Maryland Banjo Academy either.