I would pick up the AMEX EveryDay. It competes with the Chase Freedom/Chase Freedom Unlimited but unlike those two cards, you get access to full MR usage without needing a premium card. No fee, gets 2x at the grocery store, 20 transactions a month gives you a 20% bonus and it'll keep your MR safe as long as you hold the card.

That's the easier route to go if you are in a position to pickup a new card.

Otherwise, now is a good time to transfer to DL if that's your preferred airline because Federal Excise Tax is on a temporary holiday so you won't pay any taxes to transfer to DL like you normally would.