I'd like to see inventory subsets implemented similar to deck subsets.
Beside Inventory, I'd like to be able to "Create a new folder" and "Create a new Deckbox", select the subset and see the cards in there. The main Inventory would show an aggregate of all subsets.
I want to be able enter cards by the box, labeling the box so I'd know where to find them in the future. "Box" is just a semantic, it could be a binder or even a particular row in a multi-row box.