just a thought:

 something not to forget is that if you dd a tape, you're doing
a physical copy only. bpduplicate deals with image and so
will garantie each image is complete, even if splitted on
multiple medias.

 when duplicated with dd, if the original has part of image
because of spanned backups, then part of an image is the
same as no image at all.

 fx

#include <std_disclaimer.h>

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