well in short if you’re not ready to be sysadmin. Be paid user the vendor will do it for you. You can try duplicati or synchthing (combo with this Automatic backups script for Windows) as your alternative backup. If I were you, stick with linux as headless server, because windows now force update without your consent to say ‘no’ unless you mod it with custom windows os.
Ask me anything related to how to run Manager on docker with OMV os. I answer for you, since I’m using it right now. and access it using windows 10.