Please include an option to leave a friend quest, before the end of the allotted week.
This could be done after each round completion. I’m seeing in-game that a lot of players are unhappy with having other players who do little to nothing in the quest.
There’s no point in leaving the friend quest earlier since you’ll be stuck with it until the end of the week anyway and can’t choose a new one until next week. Might as well retain the possibility of completing it at least for the first round by the end of a week.
And if they have a problem with their friends’ performance in the game, they can always talk to them about it or remove them from the friend list.