Imagine the following scenario:
User A enables Skill A. Within the skill he purchases Product A.
User A then disable Skill A.
User A then re-enable Skill A.
From a developer stand-point, I have not idea that User A has already purchased the Product A as he is coming back to me with a different unique ID.
However, would Alexa remember that the product had already been entitled to the user? Or do I need to enable account linking and store the entitlement in a third party system?