I play RB and I only use gunner view and 3rd person, toggling to cockpit to gunner sometimes i misclick and go to cockpit or 1st person view.
i have no use for these camera modes and it just annoys me when i go into them as i have to think to swich back to the view i really want.
You have to assign any 2 buttons: one for 3rd person and second for gunner view.