Our files are teacher printables for student use. So they get a huge PDF with the TOC navigation to get to each chapter’s pages and can print as many as they need. That way they don’t need to scroll down to whatever page they need. The old way was to just PDF each chapter and not use a TOC, they would just download a zip of every chapter at the beginning of the school year.
On each page are a button back to the TOC (just says ‘TOC’), a button to the answer side (the next page but with answers), and the Answer Page has the same buttons but one going back to the front side. The buttons are formatted with a “Go to destination” or “Go to next/previous page.”
We have another doc where the teacher can create a test for each student. This is quite a bit more in depth with buttons that change between questions in an object state as well as questions numbers, but still an interactive PDF. We don’t use any other feature as far as the videos or animations go.