Kindle all the way. I use Calibre (free library software) if I need to change the format of a book.
Ive tried using Calbre and its producing error messages saying that the input document is incompatible. Knowing your IT expertise, this is what I've done so far. Any suggestions would be appreciated.
The source book is written in LaTeX and generates a PDF. This is a preferred format for uploading to Kindle Direct Publishing.
Kindle Create converts the PDF to KPF for Kindle without any problems. I’m currently experimenting to see if I can add hyperlinks from the table of contents to chapter headings to make it easier to navigate.
Calibre will not create an EPUB from either the PDF or KPF.
Ive tried going form LaTeX to another intermediate form, for example LaTeX to HTML then HTML to EPUB, but all formatting falls apart. Its very fiddly. It also shreds any vector graphics like the maps.
The only route that seems to work is to generate a new version of each book as DOCX then convert DOCX to EPUB. Ive tried a sample and it seems to be problem free.
Before going any further I thought I’d see if there was any demand for an EPUB version. It looks like there isn't.