This URL (with #scrollNav-2) added takes you to the first chapter on that page. #scrollNav-1 would be the top of the post. I know it’s a little unintuitive, but should let you do what you are trying to do.
Thanks, that worked nicely… Although for the post in question, Chapter 4 lines up with the scrollNav number exactly. So, the hyperlink to chapter 4 ends in #scrollNav-4. Do chapter numbers line up with scrollNav anchors when there is no content preceding the first chapter, perhaps?