I composed a book in LaTeX because I wanted the equations to be set
correctly -- and because I've been using LaTeX for decades and am most
comfortable using it.
All I know is if I send a pdf file to my Kindle with the word "convert"
in the subject line (without the quotes), the file is converted to the
Kindle format. I gleaned this *astuce* sometime, somewhere, that has
since been forgotten.
I haven't performed this maneuver in a fairly long while, though, so
things may have changed. Sometimes you are required to run as fast as you
as you can in order to remain in the same place.
The file was indeed sent to my Kindle, and it didn't land as a PDF. I can read it in the Kindle reader. The table of contents is a mess. Tables are a mess.
I downloaded everything with the same base name as I sent -- a file and a directory. LibreOffice can't read any of it. Calibre can't read any of it, either in the download or in the mounted Kindle. "file" has no idea what any of the files are.