Thanks for the replies! I hadn't considered the possibility of abuse. Knowing the way certain players of this game are, I could see people looking down on you for having "only" one class leveled, and expecting people to have multiple classes leveled for each dungeon. But I don't see how that applies to the random duty finder? That matches you up randomly, so people wouldn't be able to do that. I'm sure a solution could be found...Only allow it in the duty roulette, and only if the party # goes down to 3 people. Then the leader can choose either "Replenish ranks" or not, so that people can use their class change button (only to change to the class which is missing)

And to those saying that people could just enter as tank/healer and switch to DPS...did you not read the first post? I already suggested it should be done by vote to restrict potential abuse. It seems some people come in to topics like this with preconceived responses, like they are not willing to discuss potential changes.