SSO is still separate. From the "Licensing and Support Services" guide:
NetBackup Shared Storage Option
NetBackup Shared Storage Option dynamically shares individual tape drives, standalone or in a robotic tape library,
among multiple NetBackup Enterprise Servers and NDMP NAS systems. These servers can be a NetBackup Master
Server, NetBackup Media Server, or NetBackup SAN Media Server.
NetBackup Shared Storage Option is licensed per shared tape drive, regardless of the manufacturer, type of device, or
number of NetBackup Servers attached to the SAN. The NetBackup Shared Storage Option license is in addition to any
required NetBackup Library Based Tape Drive licenses. If the shared tape drive is not included in a tape library, then only
a Share Storage Option license is required. The Shared Storage Option is not needed when used with the NetBackup