Thats a hard question but if i had to decide would be... the option to like cancel the match if you have a troll on your team the team would vote to cancel match needed 5 votes something like that.
Someone drop the suggestion a few months ago on a post to make Lucios ultimate be affected by how high in the air he was when he activated it. So the higher he is the more sound barrier that will be activated when he hits the ground.