Couldn’t Epic simply connect the purchased assets to players accounts. Have a random serialized tag on the buyers account and product package to be loaded into the engine before it allows them finalize their game. For example if someone has a special marketplace encrypted asset they would need to validate the serial to their account that would also contain its generated serial. This could work for teams if they are under a special group connection handled by Unreal to see who is using whose serial. I’m no security specialists but its just an idea.