Idea That Probably Wouldn't Work
So right now I think a lot of the balancing issues that everyone hates is due to the fact that Rito has to balance around the competitive scene despite it being less than 1% of players. Take Taliyah for example. Abysmally low win rate, unless you go to the pro scene where she's op.
So what if Riot had a system where if you're Diamond or above, when you log in you get placed into a 'Pro Patch' and then the Pro Patch would would patched slightly differently from the main patch in order to have both high and low ELOs balanced.
Yes this would probably not work due to the time and energy Riot would need to invest into it, but I think it's a decent idea to fix this issue