So when did Amazon start accepting epub files with Kindle Direct Publishing? Back on June 8 when I posted this link it did not say epub but now it does.
https://kdp.amazon.com/en_US/help/topic/G200634390
But things are still less than wonderful in my opinion because while KDP does accept epubs, Kindle Create does not; it still only accepts DOC, DOCX, and PDF, according to their web page. I installed it and when I go to create a new project it only allows DOC and DOCX, no PDF. It's annoying and disappointing that it still doesn't accept EPUB.
But then I saw a link to their Kindle Previewer which they say accepts EPUB so I installed that. And it does. And it has an export option as well but it only exports to MOBI and it warns that it won't use the advanced stuff, what KFX provides I'm guessing.
So for my little stuff, books I'm only uploading here, I create in Sigil as EPUB 3. If I can piggyback onto Zohaib Ahmed's question, what would be the cleanest way to create from my EPUBs a DOC or DOCX file that I can then feed to KDP? I'm guessing that DOCX would be the better format.