Simple way to increase ip gains

I'm not sure if this has been brought up before, but I feel a good way to increase ip gains is to give a small boost depending on the mastery rank of the champion you are using. Something small like:

5% for a lvl 5 10% for a lvl 6 15% for a lvl 7

These gains would be meaningful in the long run when playing your favorite champions but not so much that it would make it grindy to only play your most mastered champions. It would only add around 5-15 ip per game and would make it even more rewarding to play champions you love. People are mad that it takes too much blue essence to upgrade your mastery tiers and since you have to play different champions to get boxes you can't even play the champion you are trying to master. I understand Riot is going sell champion shards for 1700 ip in the next patch, but I feel these small boosts would be helpful in attaining these shards as well.

Just a thought.