Just finished the writing stage of my deep dive on Jason White video, and learned a lot during researching.
On his podcast interview, he was asked if he had any say on his level of involvement with Green Day, because the interviewer had been a touring guitarist for his friends Portugal The Man, and they were hesitant to hire friends full time because so many friends hadn't worked out.
I loved Jason's response to this. He said he's not the best guitar player Green Day could get. He was asked to do it because he WAS such good friends with Billie, and that he has grown closer with the other guys over the years.
And as for being "the fourth", he said he never really was an official member. It's always gonna be Billie, Mike, Tre. That the trilogy simply required more of a live recording style than the other records, and he allowed the recording to go faster.
What a cool cat. Possibly smoother than Dirnty himself.