I'll might take a look if I have time after the patches, firmware investigations, koboutils updates, and some NickelMenu updates. Right now, I'm also working on a major kepubify update, which should be at least 2.5x faster for most people due to some concurrency and zip archive improvements (there's still a bit more room for improvement, since the regexp matching for sentences takes quite a bit of time and can probably be faster if rewritten by hand), will probably also have a web version which works locally and doesn't require sending your files anywhere (it'll be much slower since it's single-threaded, though), will have much cleaner code with better tests, and will correctly detect misnamed HTML files.
Sorry about my lack of response over the last month; I've been extremely busy.
And for kepubify, if anyone wants to see the in-progress code:
https://github.com/pgaskin/kepubify/network.