Legendgary-I remember that old school new york rapper who gave props to Ant Banks & Spice 1 in a song back in the '90s, he was called Daddy-O. The line went
"Now this ain't Oaktown, it's New York son/
But the funk still flows like it does with Ant Banks and Spice 1/"
...so Jin technicaly ain't the first.
Problem with this though, is that Jin is really fuckin hated. Most people ain't even tryin to hear him, so it's not like fuckin Jay-Z or whoever gave props to the bay. I mean it's cool that he does, and it's rare that someone from the east coast actually shows love for the bay, but it's not like he is east coast hip-hop; he's the underdog, just like bay rap is the underdog.