Does the SC01 code not change to something else like SC05 or SC04 if/when the previous owner turns it to a time-limited option? ie- If I can confirm that a vehicle has SC01, is that not enough to know that it will be there for the lifetime of the vehicle?
So if the owner of an S/X exercises the offer to get N years of free Supercharging on a new S/X, SC01 goes away altogether on the old S/X. It's not replaced by SC05. As I understand things (caveat: haven't done this myself), this happens at the time of taking delivery on the new vehicle, and it can only happen while they still own the car.
Hypothetically, let's say I sell you my Model S (with its lifetime FUSC) as a private party sale. It should in theory keep its SC01 option code and you should have this for the remaining life of the vehicle. Once ownership has been transferred to you, I can't retroactively "use" that to get 6 years of FUSC on a new S/X and take it away from you, because that old Model S is no longer my vehicle. And there is no time limit on SC01.
This is something I've probably said before...many owners (and prospective owners) think that free unlimited Supercharging is more valuable than it actually turns out to be.
Hope this helps!
Bruce.