Hey Dom, thanks for the feature request! I think adding chapter marks should already be possible, by embedding the chapter information into the audio file you're uploading to Steady, using a tool like Auphonic, Forecast or the "Podcast Chapters" app. I think most of the major podcast clients will support this feature out of the box.

If I understand you correctly, your request refers to adding chapter marks to the Steady RSS feed, right? We'd need to explore that further, especially around how we'd provide an interface for it that doesn't cause a lot of extra work for you as a podcaster.