I have the following setup:

Backing up to disk storage units which have Maximum Fragment size of 524Gb. Then we use Vault to duplicate the disk backups to tape (LTO4). The max frag size on the LTO4 storage unit is 1Tb.

Does the duplication process use the tape max frag? So if I have to restore a file at the end from fragment 2, from the duplicate tape copy, NB will need to scan an entire 1tb fragment?
Also, does the tape fragment size matter (in terms of restore performance), if I need to recover from the last full backup + any subsequent incrmentals?

Thanks