@Riot Idea for Champion Shards

I was thinking that it would be useful if you could convert 3 of the same champion shards into 1 champ permanent shard of that champ. This would be a bit useful for unlocking champion mastery. Instead of using 3900 blue essence to get Mastery 7 on Ashe, I could convert 3 Ashe champion shards which is worth a total of 810 blue essence. I'd be saving 3100 blue essence. This is perfect since I own all the champs. I can just stock up on champion shards from leveling up and save my blue essence for new champs as they come out or for the blue essence shop. What do you guys think?