Please add an option to trade your cards in for alternate artwork/sets. I hate having 3 of one card from 1 set and 1 of the same card from another to form a playset. If they're the same rarity/card, we should be able to exchange in whichever set we want to form a solid 4 card playset from one set or another.

This could also be implemented to allow for other artworks to be used. I understand there's currently a way to change artworks on cards, but unless you own enough of the other artwork that you like, you have to split between a couple different sets for the same card to make a playset.

Basically I'd like to pick my favorite version of a particular card, and if I own 4 of that card (regardless of what set or combination of sets that it's from) I should be able to use any of the available artworks for that card so that I can use them as a playset.

This isn't paper Magic, and there should be some benefits and differences to having a digital collection. This is non-game breaking because you're not changing the actual contents of a collection. If you wanted to, you could even allow a "1 time exchange" per card with no option to go back once it's done, if needed.