It's a handy and nice solution and everytime getting closer from your goal.
I tried it with a big odt file and I looked at the output in Sigil (we still need to use it).
1. It was splitted in 14 xhtml files with an external file sheet. Wonderful. The only problem was that these files were in presented in random order. It was easy with Sigil to restore the legible arithmetical order using drag and drop but it seems this should not happen.
2. You choose to pre-set Georgia Garamond font. Why not? I think the font-family shoudl be written only once in your sheet-file, so as to allow a quick change if your user wishes it.
I did not have time to test more thoroughly. I'll try to do better next time. Congratulations for your steady progress.
