Give users the option to customize the number of pages or minutes that are counted towards page and minute goals. For example, a book is a certain number of pages but a large number of pages are excerpts or sneak peaks of other books. Also, have the option to exclude peaks and extra chapters in an audiobook total time. also be able to indicate what page number the book starts on. This is helpful when the author accidentally includes the front matter into the page count. I attached an example of a screenshot of a book where the first page starts on Page 6.