@vampiregrave, I like your epub and its classic look.
I did some tests on the KT (Kobo Touch) and the Sony, and of course, I met the same problems you faced.
- With the Sony it goes a little better than the KT but the two failed before "Mais antigo na Espanha que o Condado Portucalense..." and "O Fidalgo encolhera os ombros..."
- My suggestion (lpara) does not work, at least with your original file.
- So I modified your epub. I removed the embedded font and added the codes you know about widows and orphans.
- With the KT it goes better than before, but not perfectly (there are still gaps in the pages). But if, as I have already pointed out, we change the name to kepub.epub, it works as expected. So there is a known bug on the Kobo which affects epub files but not "kepub".
- With the Sony the "revised" epub works correctly (no need to rename it!).
I guess the bug of the Kobo with long paragraph will eventually be corrected, so be patient. I wonder otherwise if it would be usefull to have a mechanism like : {paragraph-wrap: break-paragraph;}?