I don't mean to speak out against Bruce Barnbaum. He is enthusiastic and he encourages giving film sufficient exposure. So that's not bad.

If I shortchange him by summarizing his approach as "expose shadows on Zone IV", it's because of his video which emphasizes that.

But if you do take his approach, don't use "half box speed" as that would push you one more stop. At that rate you would be exposing your shadows at what the light meter says, Zone V. So you have to be thoughtful if you mix your mentors.