Daily Free Card/Chest

I think the current MP reward system is fine, but I've never so far had time to do more than 6 chests anyway. I like it that if I have a busy day I don't feel like missing too much if I only play that one win. If, say, the 6th chest was legendary, I would feel like I have to grind up to that each day which would make it a chore.
I am all for a daily specific quest having bonus loot since anything that makes us go back to some seldom visited quests is a nice change of pace, but it requires some coding effort of course. Or some way to handicap yourself to improve loot rewards besides the existing quests, like getting some bonus to loot for completing a quest on lower level characters but you could decide how low you want to go...

EDIT: If having high ranking could add something to MP rewards that would be great, too. A certain incentive to maintain a high rank for those who don't care it otherwise for some (weird) reason.