Still waiting for this feature..
Biggest problem in league is "Chat" toxicity" Game has been out 4 + years and still has not added this option.. Yet Riot will spend tons of hours trying to come up with ways to punish toxic players..
Here is a simple idea... ADD A DISABLE CHAT OPTION DERP! Majority of people want it , in fact so much people went as far as going into game.cfg and changing the chat window size so it doesn't even appear in the game.
I'm talking a disable chat feature that disables chat completely in-game so even if people want to be toxic they can't. This wouldn't affect pre-game chat as you need to know who is going where but as for in-game chat, you don't need it to communicate with team, that is what pings are for.
SO ADD IT
Otherwise keep spending countless man hours and money trying to figure out how to deal with toxicity... meanwhile the solution is right in front of your face.