I'm not sure if you guys make back-up copies of your maps in case the PB2 storage server crashes or whatever but I have my PB2 map files saved on my computer, Google Drive, and on a separate USB drive. I know some people call me crazy for doing this but I find it a lot safer to save your map files elsewhere and not only on the PB2 site.
I'm curious about what you guys do so feel free to comment below!