My core idea is to improve more backup options for few of our critical users and systems, by adding ODfB (cloud like) along with local.
Your core idea is wrong because you are using a sync service as a backup, and that is not the intent.
Can you hack things to make it do it? Sure. But it will never be a reliable solution.
I can understand how bad to use sync service as a backup. That's why I am here to put my plans and know possibilities, good and bad things.
Some of users never use OneDrive at all. What if I say, I will backup to OneDrive, where it is not used for syncing purpose, and backup software supports pushing data to OneDrive storage directly (if possible, is it??).....