Considering a best practise - in the event of an upgrade crash & database fails to restore:- most of the Consultants, I've spoken to regarding this topic - clearly backup each policy by clicking on each one separately and exporting them in the XML format on the hard drive.
In some environments, the individual policy count is quite high, especially the ones running discover extensively. In such cases, it takes a long time, to perform a local policy backup in the XML format.
A 'Backup-all-Policies' (with an option to choose which policies using checkboxes) & 'Restore-all-Policies' (with an option to choose which policies using checkboxes) would certainly benefit a large user base.