I'd rather have someone appointed "all the time" so the Mediator can actually function as a moderator that can actively intervene in letting our people's rights be secured, even if he is not a forum admin, he can request modifications to benefit the participation of citizens. An example would be when someone wants to form a party, this way the Mediator can assure the citizens that they can do it and, if he cannot accommodate their rights, he'd advise admins to do so. Being there "all the time" would also allow people to question the mediator as legal counsel or legislative counsel if necessary.