As in other threads posted about this same topic, I'm all for adding a short lockout timer when withdrawing from duty several times in a given time frame. Don't make it too big, but make it big enough so that A) the in-progress fishers can't, well, fish as much, and B) potentially make people more attentive of their Duty Status window. Having it grow longer after continued withdrawals would work as well. To counter the argument of "but what about the people who have emergencies?" - give some leeway, maybe 3 withdraws, before actually applying penalties. Someone who actually does have an emergency won't be re-queueing more than once.