Addition to Hextech Crafting

I know there have been a LOT of people who have come across this problem already: you re-roll 3 shards in the Hextech Crafting menu and it gives you a new permanent... Except it's either one you can't use (such as not owning the champion for a skin permanent) or one you already own.

Of course, since you can't use it, your only options are to wait until you can (again, skin permanents) or reroll it, which is a waste because it doesn't count as more than one item even though you already used 3 shards to make it.

I had an idea, however, while doing some re-rolling earlier today: what if, in the event that a permanent made through re-rolling is put into your crafting inventory, you could spend some of the appropriate kind of essence to turn that permanent into another random one of the same kind?