You did read the Sticky as background?
https://www.mobileread.com/forums/sho...d.php?t=118605
Personally, I would go with EPUB because I use Sigil and the (Calibre) ebook-editor to clean things up (and some cleanup will almost be needed 100% of the time). I find it simpler to 'Look and Clean' rather than 'Trial and Error' finding the magic terms, using the conversion tool features.
YMMV