One of my next projects is I want to build Primordial decks to start using a lot of the chafe in my collection.

https://primordialformat.com/

TlDr; 40 card format, all cards from the same set code. Only 2 rares in the deck, and they must be different. Only 6 Uncommons and no more than 2 of the same Uncommon. Everything else is fair game.

I don't anticipate this being a high priority, and can work around it until implemented. But just wanted to throw it out there just in case its a lot easier to add than I think.