Earning Chest Shards for one trick players

Can you guys add chest shards in the game for players who earn S- and above with the same champ. I want to get better with certain champs and earn crest rewards. Getting a S rank on a champ I won't play again until next year when chest resets seem like a waste of time when I can instead earn through my mains and getting better. Seems like a better reward for players who specialize few certain champs. 3 chest shards convert to 1 chest.