Does formal English grammar require that appositives be in the same person? For example,
John, my friend, works at the diner.
Here both John and friend are in the third person.
However, what about a sentence such as this:
I beg you, the reader, to give these writings a chance.
Here we have the third person reader in apposition to the second person you. Is such a sentence outside the realm of formal grammar? Or is there no grammar rule requiring appositives to have identical persons?