@NiLuJe That sounds great. But sorry for my ignorance, I don't understand how to make a mobi file (to send to a device) from the contents of the mobi7 (or mobi8) folders produced by Mobi-unpack?
(I only know how to modify the kindlegen source and drop the opf file onto Previewer to run Kindlegen again.)
I also don't know how to make a new version of Mobi-unpack using your patch file. I'm a beginner at all this.