From the point of view of a veteran 🙂 who has only done DO a couple of times. It’s a really good role to get noticed for promotions but is seen as a bit of a bum role. Keep it that way, let those who want the fast track to promotion volunteer for it and make sure it will help in the boosting up the ranks. Maybe make it a requirement to do it X amount of times to get the promotion. If somebody wanted to volunteer for it week after week they’d make their quota quicker and extra DO duties may flag officers up for early command duties. I don’t think you need to tie DO duty for several weeks just dangle a bigger carrot to the role. Maybe have a DO captained ship? I’m thinking the TSN DOnut would be fun to captain 🙂 different crew each week, an older TSN light cruiser would be perfect.