The Persistent Folder should not appear as an external device in the Files browser
Right now it appears as an external device in both the Files browser and the Gtk file chooser with a useless error message when the user clicks on its "Eject" button:
It shouldn't be listed as an external device like this as there's no use for it.
User research findings
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information