Footnotes was just an example. You can put them inline in the text, or at the end of the chapter, or at the end of the book. You automatically get hyperlinks both to the footnote and back again.
Another example is the TOC formatting. An eBook may well need a different TOC format to the printed book, e.g. No page numbers. Perhaps an extra level of hierarchy. The plugin lets you choose to use the TOC in the book, or replace it for the export with a different TOC it makes itself with different structure and formatting.
RTF export. Thanks for that. It is obvious once you realise you can only export a story to RTF, not the whole document.