title_body: EPUB Page number values
upvoted_answer: Support for actual page numbers is practically non-existent on almost all e-readers. You've tagged this epub3—I'll point out that epub3 support is also practically non-existent...
  
  I don't think using non-integer values is going to cause issues on many readers, because I doubt many of them will care. I also don't think many of them will break on the page, unless you have explicit css to force a page break.