I have the same question. Currently, I don't need to use PP lounges because I have CX Diamond status. Sooner or later, I will stop traveling for business and lose my FF status. If I have multiple PP cards, I cannot think of any additional benefit, other than bringing more people to the lounge? Same as the OP's question, does PP know it's dealing with the same person? There must be a lot of people who have multiple PP cards. What are the additional benefits? Thanks.