Lobby Vetos?
Would it be a good idea for ranked/draft modes to have to option to 4 man vote someone out? Obviously it would need to be a little more complicated than that since there is a difference between not Meta and Trolling. But there's a lot of times where good and nice players have to dodge a game to avoid being penalized by another player's bad behavior before a game even starts.
It would have to definitely to be all 4 other players agreeing, which unfortunately would still allow for duo trolling but I think it would help some. And maybe have it set up in a way so that YOU can only initiate so many votes so often to prevent players from trying to abuse it every single lobby.
Top:
Jungle:
Mid:
ADC:
Support: 