Almost every healer also plays a DD, so don’t just give players chests, give them a real incentive: faster invites for their DD. Players could choose between faster invites or chests.
For example, if you play five Solo Queue rounds as a healer, you get a one-time priority invite for your DD. The number is just an example, the concept is what matters.
I’m sure this would motivate more players to queue as healer in between, just to secure a faster DPS queue afterward. This could at least help reduce the healer shortage in Arena.
Just an idea. What do you think?