[cybmole]

ok - so can you predict what happens with a split chapter i.e. if we have
ch1-part1.html
ch1-part2.html
ch1-part3.html
ch2-complete.html
in epub
but toc only pointing once at the 1st & last files

what footer titles & counts will we see, if we sideload that through the kepub driver, & will we see extra generated TOC entries for the middle 2 fiels ?

PS I leave the 260k limit default intact in calibre, just in case I ever switch to a reader that still needs that. I still have one old Sony reader for emergencies!

there's another case. I have some books where the chapter number is always in a separate filel from th chapter text - usually caused calibre's default structure detection rules when silly people use chapter as a CSS class

so you get
ch1-0.html
ch1-1.html
ch2-0.html
ch2-1.html

etc.
in the 1st file of each pair is just the chapter number or title, in the 2nd file is the body text.

and that is such a pain to reverse - I never figured out how to automate recombining each pair so I leave it be, usually. I think the kepub renderer is not going to like that setup.