I am wondering if anyone has any experience with this
Fortunately, understanding all of this is just a part of my job and we heavily researched all of this quite some while ago and I am happy to share what I know.
A lot of the information provided on this thread is correct but unfortuntely either out of date or not specifically relevant in this particular case.
LR first introduced Keyless start / Entry in 2010 in their vehicles with the Remote Function Actuator (RFA) or Keyless Vehicle Module (KVM) ECU. Back then depending on the model the hardware numbers started with AH22, AH32 or AH42.
The inital A translates into 10 in Hexidecimal, indicating the year.
In inital attempts to address the now well known security vunerabilities this introduced, there were a number of software updates released for these, In a loosing battle LR introduced the BJ32 RFA / KVM hardware, followed also with a number of software updates and then my own personal favorite of the DPLA that you have to upload some code to before you can get it to learn new Key. I have about 3 of these
However this was still not a total solution and last I knew was that in 2015 they introduced and started fitting the FK72 as standard.
A New vehicle delivered to a dealer has an FK72 that has the code within it to learn new (Virgin) keys allowing dealers to add additional keys at that point in time, but part of the PDI process removes that code that cannot later be re installed.
Therfore dealers retro adding new keys in 2015 on vehicles with the FK72 involves replacing the FK72 RFA / KVM. Of course dealers have have some exchange scheme in place.
In our low level research, we have actually figured out how to virginise used 2010 keys, and alhough I have about 10 virgin keys in stock, 8 uncut emergency key blanks along with 3 new FK72 RFA / KVM's and a 2016 DS that has only one Key and also have the same kinda wife, I also have other things that take higher priority than this.
In summation though, even if you managed to get aa Virgin Key on EBay, as an owner of a 2015 on vehicle with an FK72 you also need a virgin RFA / KVM and a someone to reprogram you old and new Key to it.
Hope this helps