Trade dupes for costume

There is little more disappointing than when the RNG gives you a dupe of a particular hero (rare enough to begin with) only for that hero to get a costume a short time later.

But what if you could trade in heroes for their costumes? Maybe have something where every time the Costume is available to be pulled, you could trade a hero for their costume (e.g. trade a spare Kageburado for his costume), once per such event. Or instead of having it on a per event basis (Atlantis, Valhalla, etc), it would be just in the Costume event?