Where are the offline files stored on Android, and how is that location maintained?
Experimenting with a Moto G4 I chose a file in Dropbox and selected "Available offline" then used a File Manager and found the file in:
root/sdcard/Android/data/com.dropbox.android/files/u1234567/scratch
What is the `u1234567` portion? Is it a user partition? Is that value consistent for the same user across devices, or is it unique per device? Does it change after time, and if so, when and why?