As I understand the theory, it is for things you may, or may not, produce. If you at a future point would decide to write a book, paper, blogpost, design draft,

As I understand the theory, it is for things you may, or may not, produce. If you at a future point would decide to write a book, paper, blogpost, design draft, manifesto, or anything of that sort, about things that you currently find interesting. Then ZK is about moving the note taking part of that future work to doing it now. With the option of using it for something completely different if that work changes your understanding and interests along the way.