Ability to Downgrade a cover

You know how frustrating it is to win a 14th 4* cover that you don’t have the ISO to max out currently? Or heavens forbid, the 6th 5* cover that’s not championed?

What if there was a way we could down from a 4* to a 3*? I’d much rather be able to use that 4* to boost up one of my favorite 3s, instead of just selling it for 1000 ISO. And same with a 5 to a 4*. That would be quite nice!!!