While this sounds like a decent idea, the point of m6/7 is that you consistently do well. You can hit an S+ by being lucky (especially so for some champions). Sure, it takes skill, but it's still a lot of luck. It makes no sense that someone who always plays a champion well would take more games to get m6/7 than someone who was just lucky as hell one or two games (Say, as
, where your top and mid are just that good, and you just press R about the right time)).
However, I agree that S+ needs some more recognition.
Maybe some other reward for S+? Maybe every certain number of them you get means you get a key (fragment) or crate, limited as it is now (i.e. you can't get a point from a champion more than once per season)?