Q: Customer wants to take an export/backup of the EOP policies and settings, so that they can revert back if required, is that possible?

A: Sort of – it is for migration from one tenant to another but has all the steps for what you are wanting, i.e. export and import.

https://docs.microsoft.com/en-us/office365/SecurityCompliance/eop/move-domains-and-settings-from-one-eop-organization-to-another-eop-organization

You can also check out the script listed in the technet gallery for this:

https://gallery.technet.microsoft.com/Migrate-EOP-Settings-9d480325