By default Thor will check to see if the file exists at the primary location when reading a file part, if it does not, it will locate a copy that exists and copy it to the primary location.

This is probably never desirable in a containized setup, and in particular when the preferred planes functionality is active, which re-orders the cluster info of a logical file to promote/prioritize the preferred planes, we want it to failover to other copies, without copying the other copies to the preferred planes automatically.