Since you are taking notes, there is something I've noticed: once a deck has been set for a certain format (example: Traditional Standard), the dropdown menu stops working and you can't change it anymore, for example: changing it to Historic to make a version of the deck that can be used in a different format.
I hope you can look into this. Other than that, I think the deck builder UI is in the best state it has ever been and the new options for filtering are great. On that, a suggestion: maybe a button that shows the advanced commands that can be used in the search bar?
Thanks a lot for reading and for your work. Cheers!