Collectible Card Game Headquarters

I'm still newish to magic, so none of my decks are "finished." I rotate in and out whenever I can actually play someone and test it. Could I build a deck, with the frequently accessed cards placed as regular unlocks to use it as a sort of sideboard?

Yes, (you can use either regular unlocks and/or promo unlocks if you have entered the 10 promo codes) though remember that the game doesn't save the deck configurations of modded decks between game sessions so whenever you start the game you would need to adjust your deck with the "sideboard" cards before playing a match.

Also remember that for multiplayer any person you play with/against must have the exact same WAD (so they would also be able to look at the "sideboard" in the in-game deck manager, but won't know exactly which cards you have traded out with the sideboard cards).

I haven't gotten to configuring multiplayer yet unfortunately =[
I wanted to see how my decks drew/handled the AI to make sure I don't have a royal POS. I'm not very good yet, heh.