Non-ranked match play
Using the "Deck Rating System" for non-ranked matches would make playing a lot more enjoyable.
I have talked to at least 30 people who have told me that they either don't play much or have deleted the Arena app altogether, because there isn't the option of playing matches that would be considered "rating 1, 2, or 3".
Example: my wife quit playing, except against the bot, because she is not a fan of rating levels above 3 IRL (she is typically between 2 & 3). Several others have told me that if Wizards would have, at least, the ability to choose 1, 2/3, & 4/5 levels to play they would love it.
Let's face it, if most people sit down for a 1 - 3 rated match and someone is only playing a removal strategy against them it is everything EXCEPT fun/enjoyable, for both sides.
When playing MTG IRL most players won't play a match against someone playing a deck that is rated 2 rating levels different.
You already have the deck builder able to differentiate between what is a legal deck or not. So, adding the "deck rating" system to the deck builder should be rather easy. And, if you do, you will have a vast portion of casual (not being sexist, a lot of female, including my wife and daughter) players using your app, falling in love with new to them cards, and hunting down those cards IRL.
Thank you for your time and consideration.