Yes x1000 please make this a permanent option. I know that it's been suggested in the past before, but I don't remember if staff ever got back to the suggestion or not.
It's bad enough people find loopholes in the rules to avoid mutes and bans from spamming/excessive trash talking. They can even put the ignore list underneath the friend's list in the lobby, so that they don't need to redo the interface where the Lobby/Friends/Clan part is. Can just scroll underneath all your friends and see a list of ignored users underneath if you need to unmute someone.