Backup and Restore instead of initial sync?

Hi there, thanks for your input. Following a related situation in another recent thread discussion, below are scenarios that I pictured:

Scenario 1, If I am in a situation of this thread subject, and I import data from my local backup file and deleted all data on Dropbox cloud storage and sync everything new up to Dropbox, in such case, nothing will be repeated, would this work?

Scenario 2, can I uninstall/re-install my Joplin app, import data from backup file, while all my notes are under one giant folder tree, I can just change the folder name of top folder, and then start the sync, and then deleted everything synced form Dropbox, in this way, even though my notes are temporarily repeated, but I can easily identify the notes synced down from cloud and delete all of them. Would this work?

I have a feeling that scenario 1 is making more sense if both of them works though.