With each deck listed on the deck search page, there should be a button that adds the 8 cards in a given deck to the “Exclude” portion of the filter. This would make building duel sets much faster (unless this already exists and I’ve been doing it the hard way). I would think this would go inline with the “like” and “copy deck” buttons.
The duel set Deck builder and deck search are great, they could work together a little better. I find myself adding the excludes manually, which sometimes means that I miss a card, or forget what cards I’m adding to exclude because the deck is several scrolls down. This slows the process and somewhat limits the ability to chase “what-ifs” quickly.