I just realized Tracer, while he technically has a character of his own, doesn't seem very fond of using it often (or perhaps it was simply for the P&C story arc). Either case -- Tracer, and anyone who doesn't have their own feel free to write for other characters.
Really, I was just aiming to have as few active heroes in this story arc as possible, in an attempt to start a trend of small groups, but if it's keeping you all from writing, then it's a bad idea.