Soul Exchange Idea

Regarding upcoming “Soul Exchange” feature where duplicate 5*s can be traded for “souls” then spent on a pre-determined set of heroes for 5/10/20 souls.

Is it possible to include in one of those groups of selectable heroes (say for 10 souls) costumes of the heroes that you already own. I think this would be a good mechanism to ensure our favorite heroes can be kept relevant. Still need to summon to get the 5*s for souls but in this way can target the heroes you like with costumes. Costumes in general just keep old heroes relevant so I don’t see it being OP.

Thanks.