I have recordings but no book yet. Can I use BookyAI Listen without creating a book first?

Yes, from version 1.9.15. On the Listen tab, under "Save to", choose "Listen library (no book yet)" and add your recordings. Nothing has to exist beforehand, and BookyAI remembers this choice. The transcripts are kept in the Listen library with their summary, key points, quotes and chapters. When you are ready, tick the finished recordings and click "Write a book from these": the wizard creates the new book and gives it its own copy of the transcripts. Removing a library recording from the list also removes its transcript. BookyAI Listen is a paid add-on.