When I deck build I tend to search a lot using scryfall and then when I see something I like and think I own, I check deckbox. This is inefficient and I frequently make mistakes in both directions.

It would be absolutely lovely if more and more scryfall info made its way into the search paramaters. The two that would be most helpful for me are "keyword" and "otag". Keyword seem seasy assuming you are already using the Scryfall data dump, but otag is likely more difficult since it isn't exposed from what I can see.