The Windows device manager should see two devices... a medium changer, and the drives themselves. BE then interprets that and it gets listed as a device there... Hopefully though, just a single drive will suffice for you for the time being.
It's supported in 10D, but probably not further back than that.
I've take a look for a BEWS 8.6 HCL and found nothing...
If BEWS doesn't detect the changer correctly, it won't move your media around, so you're stuck with hardware that won't move media around.