using covers to upgrade character levels not just skills

Thor seems to love me from hero tokens... I have a maxed 5/3/5 thor and i've received no less than 5 red covers and 3 yellow covers since I maxed him out... It stings every time I sell them for a paltry 125crystals but i've hit the inventory cap, cache time running out, what else can you do?

even worse on moonstone, i spent some HP buying packs last time and got 7 red covers and 1 purple. I sold these too and selling a HP purchase for 125 crystals is an abysmal conversion rate but there is no other option.

I really dread seeing covers for characters I already own. It puts me off spending HP on packs once the featured character is already maxed in a skill because it makes it useless. openinig packs should be exciting not dissappointing and certainly not reinforce a feeling not to spend real $$ on HP.

So that's the long way of saying I'd love to see us be able to use covers to upgrade character levels in addition to skills. this then gives me something useful to do with my 7th red moonstone cover. it makes me excited to keep trying for moonstone packs because i know it can be used to level up if i get the wrong color.

further to this idea if you consume a cover that has already been trained it would be worth as many levels as training. so consuming a 3/1 thor could be worth 4 levels to his upgrade. Arguably this is better done at the 50+ levels of thor but i have to wait a long time training him up there myself all the while the feeder thor takes up inventory space so I think this balances out.

in memory of all past thors sacrificed on the alter of crystals... here's hoping getting duplicate covers is a cause for rejoicing in the future instead of wincing