[QUOTE=jackie_w;2768234]Sorry, forgot to answer this bit. There isn't really much Kobo black magic here./QUOTE]
that is very clear, thanks & is consistent with my test results.
Yes I do calibre convert all books before reading, so as to have an original_epub backup so stuff was being added to CSS class definitions by my default preferences.
I shall now change those.
I now need ponder how best to remove explicit line-height: 1.2em; lines from new books so that line spacing controls work, as a lot of books have similar lines.
and also <a> tags. when I touch a chapter number in my current book, I get a pop-up offering to launch the kobo browser- maybe I can turn that off in Kobo, otherwise I will have to mess with code that looks like this:
<p class="title-num-rw" id="rw-title-num_65077-201898256"><a href="../Text/TOC.xhtml">3</a></p>
PS Another CSS example from same book as the above- this books styles all text messages sent by characters in the narrative with a class containing font-family:sans-serif; to make then stand out. So this is an example with automatically wiping all font-family code ( via calibre CSS filter) would affect the intended book layout. So I am inclined not to enable that calibre CSS filter as a default perference