If you are not familiar with policies on shadow volumes, you should test them against a test data set to understand how to use them to your advantage.
Add files of several different types to the new share, then either create a DST policy to move the files, or do an inventory to search for specific file types, then move them to the shadow.
SSH in as the user, or root, and look at the primary, shadow, and Shadowfs root paths to see if things are where you expect them to be.