HonKit provides a wide array of convert options for the PDF output, but none for the ePub output. Worse, it hardcodes defaults values (cf. honkit/packages/honkit/src/output/ebook/getConvertOptions.js) that it probably shouldn't. As least, HonKit should add the following general settings:

• book-producer: currently set to "HonKit", should be user-configurable
• publisher: currently set to "HonKit", should absolutely be user-configurable

Some other missing or hardcoded values could be available as general settings or ePub specific options:

• pubdate: to set the publication date of the book
• series and series-index: to set the series the book belongs to, and the index of the book in this series
• epub.toc.position: to set the position of the ToC at the end of the book instead of the start (see --epub-toc-at-end in ebook-convert options)
• epub.toc.title: to set the title of the ToC, as in some languages, a ToC at the beginning of the book has a different name as a ToC at the end of the book (eg "Sommaire" and "Table des matières" in French)

This would go a long way in making the ePub output more robust (and, speaking as a publisher, more "store-ready").

• HonKit version: 3.5.5