This might sound weird to some but Frisell helped me understand what Ken Tamplin teaches in his course. Once I got what Frisell was talking about and went back to my Ken Tamplin course, I was on my way!! I don't even think about the passagio anymore. I just think in vowel mods. Once my voice got use to those subtle changes it was a major breakthrough. I just think mid voice all the time now instead of chest or head. When people sing in chest/head mind set u r always focusing on crossing the bridge. Like Rockwell Blake said, the passagio is descriptive only and has no objective reality. It comes down to balancing the mid voice configuration. Ken definitely has it figured out and Frisell, too.