The easiest thing to do is backup those folders periodically. (And/or the whole user profile folder, since it will contain settings for other apps you might also want to backup.)
Backup tools that let you add folders, or which backup the whole system drive, will have you covered.
You can also set up a toolbar button which makes a new Opus-only backup when you click it, if you want to streamline things a bit.
Or there is this add-in which automatically creates backups: