“and he’s a member of that kehila,”
who says he is?
He has one shul he davens shacharis another for MAariv Mincha is at a minyan next door to his office . Friday night is another shul. And Shabbos day is a 5th exccept Shabbos mevarchim when he goes to the shul he davens in yet another shul in because they have a chazan .
which Kehilla does he belong to?
More importantly , why do you get to decide? He has his Rav (where he davens Maariv during the week, he loves that he gets to ask his 24 shaalas a year after Maariv) Meheche tesi that he HAS to follow every pesak from this Rav?