Maybe I can help. First I go to the area where the 9 door is and collect any Language notebooks there (It's easy to know which rooms there in thanks to the map here) and I put the codes on a separate online notepad so when I go back to wind up Phonty I can also put the codes in the elevator. Once I collect the 9th Language notebook, I go back and enter it into the elevator and wind Phonty for the last time. That way during the final chase I only have one code to remember and enter into the elevator. I also collect any Flashbangs and stamina items just to be safe.