Hi.
The only way to access the bundled version of Studio one is to register the interface to a Presonus account.
So, if you register it, when you sell the software you will then have to pay the fee for transferring the licence (around $25?).
Or else, you can give your buyer the hardware code and they can access the software directly with there being no need to transfer a licence; but as you say, you would then have an unregistered interface.