Would be hard but
1) Vote kick is placed on character
2) ACTIVE GM comes and checks log quickly to investigate matter, if the GM agrees with the vote kick request the player is then kicked out of the instance.

But that isn't realistic with the amount of players that is/will be playing this game.

- If you simply add # of mob kills then that player will just kill that amount of mobs and go AFK, so it will need some kind of progress check, but that also isn't easy thing to do so I highly doubt this method.

-If you make it where you can't kick when the chest is opened, people will just kick before it's opened. Same goes for boss fights.

Vote kick is much needed feature imo but it's really hard to control how to make it not abused. I wonder what their plan is.