improvement to champion 6/7 mastery

Gbay99 brought up a good point about how, in order to get blue essence for the rank 7 mastery for Ashe (as an example), you need to get chests by paying for chests or playing champions that aren't Ashe. To show your dedication to Ashe, you have to either pay or play champions other than Ashe. That doesn't make much sense to me. Perhaps if you win a game AND get an A rank or better with a champion you already have at level 5 or 6 mastery (not 7), you receive a bit of blue essence (maybe 25 or something). That way you can play the champion you like and still get the mastery. At 500 blue essence, it would take 20 A rank wins, which I think is a good way to prove you are good at a champion and deserve extra mastery.

Keep the current disenchant for blue essence, too.

Some may say it could be used to get champions fast by farming blue essence, but you are already, in a way, farming IP by doing that, which you can use to buy champions anyway.