yeah this is actually really irritating since i have to review in another book to even attempt to understand the passages in tbr. the second half of physics in particular leaves out a bunch of stuff in the review sections. i'm doing every third question right now so that makes it even worse. maybe i should just be doing the questions and review entirely somewhere else?
Just my two cents here, but I think you are missing the big picture of MCAT review. It's not about reviewing and rereading material. It's about learning to take the exam, learning to make good choices quickly, learning to interpret what the questions are asking, and learning to think conceptually. That is what BR books (and class) did for me more than anything.
In the end, everything I needed to know for my MCAT was in the BR books and I learned to extract it and apply the minimum information to get the correct answer fast. I ended up with a 15 on PS after starting with a doubtful hope that I could break double digits. Their method works really well, and you need to stop wasting time reading other materials and focus on passages and questions.
And as for the equation you couldn't find in their general chemistry book, it was in mine (it's equation 8.10 on page 148 and sample questions 8.16, 8.20, and 8.22 are based on it.) Just work through the problems and read their explanations, and that will give you everything you need.
Good luck and don't let the mid-review blah get you down.