I understand that "vanity business" is important part of ways how to support beloved game and I find it to be good idea, but it should not be obstacle to comfortable use of the game. I was mentioning this in some other post some time ago ...
I would very much appreciate, if it would have been possible for purpose of deckbuilding to have each card occupying just one slot in collection during deckbuilding, simply by merging regular and premium versions. If player has only regular versions of cards or only premium versions of cards, this can be workarounded by displaying cards, which are owned by player. However when player has mixed collection with some cards having only regular, some only premium and some having both versions, it is making things obnoxious, especialy the larger collection you have, the more difficult it is to navigate through cards during deckbuilding.
Would it be, please, possible to introduce some option or switch or whatever idea you come to, to make it possible? I am really not inclined to get extra premium cards, when it means lesser comfort for deckbuilding. In fact, I often just switch my collection to display only regular cards (and keep in memory those few, which I have only in premium version) to check my options for deckbuilding, but this is also less comfortable the more cards I get into my collection, so in fact it is more comfortable for me to avoid having any cards only in premium version. As a result, I anyway build my decks only from regular cards, despite I have premium version of a card, unless I really have no other choice than to use premium version.