Allow saving alt card lists with decks (separate from deck/sideboard) to make deck creation/tuning easier.
When starting a new deck and swapping in and out cards by trial and error, the current deckbuilder GUI can make it difficult, annoying, or even sometimes impossible to do that efficiently or quickly. Usually there may be 100 or so applicable cards that may go into a deck concept. You hunt down all of those cards and get to the cards you want in your deck and sideboard. While you are still creating and tuning your deck, you want quick access to the remaining cards out of the 100 you initially identified to swap in and out to hone and tune the deck. If there was a way to store those non-deck, non-sideboard cards with the deck, then when you go back to the deck editor, you have easy access to the cards that didn't make it into your deck or sideboard. This would make creating, honing, and tuning decks less frustrating, more fun, and faster.
So, aside from the decklist and the sideboard, it would speed up deck tuning to have a separate place to store cards that can be swapped in and out of the playable/sideboard cards to tweak your deck in the most efficient way. That cardlist would be saved with the deck so that candidate cards can be moved in and out of the deck and sideboard easily without hunting down those specific cards all over again.
Currently, you need to go hunt down that card that you saw hours to days earlier that is relevant to your deck if you had your deck size the way you wanted and you didn't want to use your sideboard to have cards you weren't sure belonged in your deck or sideboard.
Furthermore, various simple GUI or functional enhancements to swap cards between the deck/sideboard/extended sideboard would be very useful to accelerate the process.
For example:
Add an additional deck view in the deck builder that showed Deck, sideboard, extended sideboard side by side to allow for easy click and drag between the three. (The card pool would not necessarily need to be visible in this mode, saving screen space.) This would be much easier than the vertical view where you have to swap deck/sideboard views and can't drag/drop, or the horizontal view where the sideboard appears and disappears while making it difficult to place the card where you want it to go. This deck editor view would be specific and perfect for card swapping, and would take the frustration out of using the horizontal or vertical view to accomplish the same task.
Perhaps a quicker implementation would just have a right click menu for each card that had options like: "move to sideboard", "move to extended sideboard", "move to deck", etc. That is, the left click would have the default function (remove card, add card) and the right click would have the additional move options. I assume that would be less effort to implement than a new view and all the GUI hooks that go with it. I think option A is more elegant, option B is probably faster to implement, and both would be great.
Sincerely,
Frustrated player taking way too long to tune new decks.
Thanks.