Yes, you can add multiple duplicate IP ranges if you need to, however as these will all be duplicate IPs, it will depend on your routing as to which one IPAM can scan - all other duplicates would have to be added with Scanning disabled.
Have been testing this a little.
basically i uploaded a list of 192.168.1.0 addresses, then created a supernet over this to allocate the range into a number of individual 28 bit networks (did like that feature ;))
I then created a 192.168.1.0 /24 network which it did allow and placed this in a seperate group.
I can individually edit the IP's in the 24 bit range and the changes are not repicated to the /28 bit networks, and vice versa, which is as I would like.
But when I then uploaded a spreadsheet detailing the whole subnet, it overwrote both sets of ranges, there didn't seem to be any option about which subnet to allocate the addresses, it just wrote to all matching addresses.
Closing the loop on this thread, I have reach out to jsirrett offline to further discuss use case