The deckbuilding interface can be improved, and by allowing for better sorting and filters I believe it would be greatly improved. So, my two feature requests follow that deckbuilding should include:
1) card sorting based after applied filters
2) "advanced filters" that allow for any of the filters permitted in the search bar.

First, I believe that there should be many ways to filter your cards while deck building. Currently, it defaults to color first, mana value second, and card name third. It is obvious that there is sorting applied on the returns, but allowing a user to change the order would be superb. There are so many times when I want to sort my filters by mana first, then rarity or alphabetical, and not include color. This is a simple client side process on the returns from the server I would assume. If you need help brainstorming different sort criteria, I'd gladly assist. It would even be interesting to include cosine similarity on textual embeddings or a players "desired playstyle" with a RAG system, although I assume that's too much of a stretch goal at this moment.

Second, if a query exists in the API and especially within the search bar, it shouldn't require accessing outside resources to utilize it in game. For those unaware, look to the following page:
https://docs.google.com/document/d/1GORw3VrFSD5zTE2-XlMcerLEov0TN5L1bgo5T0WsnkE/edit?pli=1
I agree that too many filters clutter user interfaces, but these options should be included in an "advanced area" while current filters do not feel advanced at all. Or, at least provide a "query builder" that doesn't require reference to such a doc.

Neither of these asks should be difficult, and I'd be willing to assist with development. You would be better contacting me through another medium, and I am unwilling to provide either my serious email or my phone on your forum currently.