Honestly they could safely increase the drop rate based on the expected wait time that DPS suffer through. It's obviously not fair for dps to have to spend way more time then any other job. But on the same token if they were remotely worried about fairness, they wouldn't of put RNG on the drop to begin with. What's truly sad, is even with that long of a queue, its easily possible you'll finish your zodiac before a tank does. Just because of RNG, and how frequent some people have to do 40+ runs, while others only have to do 1-3 on all dungeons.