I have used PaperPile for several years in multiple collaborative projects, some of which began before PaperPile.
People I’ve recruited as PaperPile users find managing shared folders cumbersome. Here are two features that my collaborators would love.
An option for having shared folders collapsed (i.e., only parent folders shown) in the menu sidebar when PaperPile is launched. It’s tedious to scroll to the last parent folder if the parent folders above it have multiple child and grandchild folders.
Tags for shared folders. With tags, where would be less need for using subfolders for shared references.
If anyone who collaborates extensively has solutions that help in organizing shared data, I’d appreciate hearing about them.