Sorting looks buggy:
https://paperpile.com/shared/mQWi6z
https://paperpile.com/shared/1FysXR
Paperpile should sort folders and subfolders automatically (0-9, then a-z; possibly, with consideration to non-Latin scripts as well as scripts that use extended Latin character sets).
Additionally, it would be great to be able to set order (for shared folders), for example using URL parametres (sort by name, sort by date of last update, sort by size - ascending, descending).