Hi, thank you for your message.
I understand what you're trying to do, and that was actually going to be another feature called "Locked Pages", but due to time constraints I haven't been able to implement it yet. The idea was precisely that the player could unlock "pages" with switches and display a message or hide the content until that condition is met. Once I have a bit more free time, I will definitely implement that functionality in a plugin update.
Until then, you can use the "Required Switch" feature, which allows you to hide a book until the switch is active. In your case, you could perhaps divide your story into:
"My Adventure - Chapter 1/12", "My Adventure - Chapter 2/12"... and so on.