This would be a great feature. Interface that would let a user renumber image IDs with a jQuery sort (draggable images) would be a good, intuitive way to do so… Alas, I’m not a programmer . Found some info on doing it for WP post attachments, but am unable to translate the info to BP Album+.
In BP-Media 0.1.9, users can sort both albums and media items. Our jQuery front-end works similarly to the article you referenced, however we have a more efficient way of doing the ordering on the SQL back-end.