I keep my Schoeps caps all wired up to my preamp. I just keep them in DPA UA0896 screens when in transport and indoors. These are relatively newer screens and they DO NOT shed. I just tested them and got ZERO shedding
I probably should store them in a small pelican or the like, but this works out perfectly when just traveling to Pittsburgh or so. Keeps my caps in MINT condition[since the screens never come off] and its super lo-pro
As always, YMMV, but I have never had a problem storing active caps like this and Ill continue to store them that way unless I feel its unsafe, which hasent happened to me since I bought actives in 2007!!!