I'm a very basic user so please forgive if my response is not helpful. We are running a very similar scenario on BESR 8.0. We have no problem rotating out portable drives out every night. The backup destination (E) is selected in BESR. We have 5 rotating disks named Image 1, Image 2, etc... through Image 5. When I look at the BESR software, it specifies that the backup will go to destination drive E [Image 1], for example. If I remove disk 1 and put in disk 2, the destination changes to drive E [Image 2]. The software seems to take care of it. If that fails to work for you, you could always consider changing the name of your portable drives to be the same, I.E. name them all' Image'. Hope this helps.
