Feature Request (Mobile): Export individual notes or sub-notebooks

I'd like to use Joplin to support a group of people in the field taking notes, then uploading JEX exports of individual notes, subnotebooks or whole notebooks into a central Joplin instance running on a laptop - the current Android app only seems to have the ability to export the entire database each time. I've looked at using Joplin Server, but there may be scenarios where network access isn't possible and we'll have to 'upload' JEX files using Bluetooth or even USB drives.