Well I only know about from this thread. My reading of it above was that it is enabled through firmware. "License" means software, in my mind. Unit specific license means software.
When I first heard about Puccinni/Paganini, the very first thing that came to mind was "but does it upsample external sources?" I actually commented in another thread, quite a while ago, that the whole Paganini/Puccinni line was decidedly music server unfriendly because of the way the upsampler is built into the transport. This was, in my mind, an obvious and (probably an intentional) omission on the part of dCS. Are you telling me that the hardware exists for upsampling of external sources but they have only recently developed the firmware for that? I think not. Most likely they saw/see servers as a threat to their high-end cd transport business and intentionally omitted this functionality. It gives their transports a built in performance advantage. It also allows them to sell a redundant (but possibly improved) upsampler in their Scarlatti line.