this is a great plugin and I love to play around on my local installation of my podcast. I gave some thoughts how to improve use of the plug in.
So, I have two suggestions that might be useful:
1. I think the podcast audience is expecting information about start times of chapters, chapter duration might be the second important information
2. It would be very useful to link chapter marks. Why? For many podcasts chapter marks and shownotes are the same. So the web player can include all necessary information the audience needs - the blog post could be very compact.