I think the immobilization is key here and not something I would trust from any third party. If a third party has access to the encryption method, so does a hacker with the right tools.
Additionally, it's configured to the VIN specifically so you can't steal or buy genuine parts with a key you have access to and swap them into a vehicle that those parts don't belong to. Chop shops have the ability to do this in the event that these modules aren't configured properly and don't require the right validation from other modules.