The decklist viewer currently lets me see a checkmark of different colors based on whether I am missing the card, have the card but a different printing than the list, or the same printing. Unfortunately this pulls from your entire collection regardless of whether you have the card on paper, MTGO, or Arena. This makes it difficult to actually know whether I have the cards for a deck, as if I own some of them on MTGO and some in paper, it can tell me I own the whole deck when I do not on any platform.
I would like an option (along with a user-settable default) to tell my decks whether to check my paper, MTGO, or Arena collections to determine ownership of a deck.