I first found John Forester's book in the library in the 90s, and it felt like a tome of secret, special knowledge. Then, I read more of it, and it did not match my experiences.

Jason Slaughter has now done a very extensive takedown video on his Not Just Bikes channel, which is far more congruent with what I have seen. Taking the lane is effective when there's no other choice, when it's too narrow for cars to pass, but drivers will try anyway.

Otherwise, there's very little that's safe about it.