Cannot help you with the main part. But While you can restore from tape, it will just stage it on the disk.
You will want to Duplicate to Disk like you have done. If you do not, every time there is a error with the restore the job will stage to disk. When the data is duplicated to disk, it saves you time in case there are any issues with the restore.
An option could be to mount the storage group as a recovery storage group in exchange and use the shell to copy the contents of the folder over to the new location.