I will say that the enzyme issue was a problem for me too, especially in Elementary School. they only allowed the school nurse to give me my enzymes and sometimes she would leave me sitting there and I would miss most of lunch. So when i went to sixth grade we didn't say a thing about the enzymes and my mom packed them in tinfoil along with my lunch. I became an expert at sneaking them in at lunch so that the teachers wouldn't catch me. I did that all through high school too.
I never had any sort of special plan in place. In Middle School, my mom and I both spoke to all of my teachers about CF. In High School and college, it was my resonsbility to address the issue. Freshman year of college, i didn't tell any of my professors about CF. When I became more ill my Sophomore and Junior year, I spoke to all of my professors before classes started and told them the issues. So some find it necessary to have a legal document in place, I personally did fine without one!