bro. since u have already done this.. can u check one thing.. it seems I can add my cousin to my microsoft account as family then he will also be able to enjoy my purchase.. will it work for this too?
If you have second console in family, you can use same creditials (having GPU subscription) to add user, once added make the console as "Home console" and later you can delete the GPU profile, the second user will get the same benefits of GPU.
Steps I read on reddit - Link
Do check the first comment, which allows us to remove the login creditials too!