Ultimately, you cannot force people to stay in a Duty they find unfavourable-- or unbearable-- to their gameplay. Force them and they'll just circumvent the situation by looking for methods to be kicked-- the basic fundamental solution is to increase the rewards and give them a proper incentive to pour their time into it.
Besides, the problem is not as rampant as before --especially now that several people amassing poetics for their relics would rather run Castrum than Praetorium.
