Removing the Onedrive Documents folder?
What MS never explicitly tells you is that turning on "Backup" for a folder
re-directs the folder location from its default:
%USERPROFILE%\<FolderName>
to
%USERPROFILE%\OneDrive\<FolderName>
and moves any files found in the default Documents to the OneDrive Documents.
Turning off "Backup" will restore the default location, but (IIRC), you have to move the files manually.
With "Backup" turned off, only those files you explicitly save or move the the OneDrive folders will be synced with the cloud storage.