Why do you add an ability to mute players in a quick join lobby, if you cant mute people in-game?
Not sure but i think you can mute someone ingame… but a mute button always comes in handy… especially cause many people just span the chat or make inappropriate statements
I think you can mute/unmute whenever you are with command
/mute [player’s name]
/unmute [player’s name]
~Type it without these 
You can right-click a username in chat to mute them