It drives me crazy too. Like it's next to impossible to put anything else in a scene with Vicky 3, or Koshini, who each have their own sets of folders, without going through hoops. And I keep my references pristine. You can, though, minimize Poser, and go in with Explorer (or PBoost actually) and move the folders you want from one bank to another. Kind of defeats the purpose of the banks but it works.