Generally I would not take more than 30 seconds to look at an exhibit. This is typically enough to get the main points.
During that time, you can write down whatever you want. Figure our a way that works for you, not for others. In my experience that is not needed. I'd rather recommend to only note down the key insihgts at the end of every branch of your framework. Taking notes is a supporting tool for you, not for the interviewer, so if it helps you focus, note down everything you want.
Here's a post I wrote on note taking that might be helpful: https://www.preplounge.com/en/consulting-forum/how-to-improve-notes-taking-during-case-interview-8965