Hey,
You should already be able to see which cards are available. If you link the deck cards with the inventory printings especially, you will see where the cards in you inventory are used. Make sure to also enable the "Decks Count" extra column on the deck listing page. (in the table header).
Hey thanks for the reply.
I assigned specific printings in all of my decks. But when I build new decks, I would expect the dropdowns to only contain non assigned cards from my inventory. But I do see every printing I own. Lets say, I want to ad a Sol Ring to a new deck. I have 7 Sol Rings in my inventory but all of them are used in decks and linked to the specific version in the deck. In the Deck Building view, if i check "From Inventory" and search for sol ring, I can still see all the printings in my inventory. The same happens if I select a printing in an already added card via the "Owned (Inventory)" Dropdown.