Request: Allow "source and parameter to --backup-dir" to overlap, if --exclude "/backup-dir/**" is set. This way, the backup-dir can exist in the root of the sync pair.
Requirement: Because of the existing issues with SharePoint Online, the recommendation is to use "--backup-dir Sharepoint:Something". The issue I run into is that most often, I'm moving a single share to the root of a single Document Collection, so it's just not possible to use "--backup-dir".
Before anyone says clone it to a folder in the root of the Document Collection and then move it ... Give that a try with 1mil files and a deep folder structure . It's just not worth it.
I run into this one pretty much every time I migrate someone to SharePoint Online, which of course, I'm doing as I type.