When I break up my books, I do as Mncowboy, every new
page subject type, that includes a separate dedication page, even when only a few lines. Pretty much what you see in a Paper edition. If it starts
on a New page.
Be aware 'Chapter' is just a term. Any single block (file) of text must be under 260K for (older?) ADE mobile devices. Smaller means faster rendering on page or Zoom level changes
. A 260K page will load and render... It just takes forever