What about non-iPad devices, what about iPad #X (future device)?
What about iPhone? I could see hyphenation enabling/disabling causing a much worse problem when you don't have much left/right space available to fit many characters.
What about someone who reads on an iPhone with huge margins on the edges? What about someone that reads with no margins? What about someone who chooses their own fonts? What about someone who wants to read in Marvin instead? *Insert huge list of changes/questions here*.
What if they want to convert this EPUB to Format X and read it in Program XYZ? Your hyphenation code will most likely not be transferred over at all. (And at worst, might get in the way/break something else... for example, soft-hyphens, while they "look nice", break search functionality in many devices).
You should stay as out of the way of the user/reader as possible, and only giving very general guidance with your CSS to tell the device how to treat the book.
It goes back to the ol' argument between "specific" versus the "broad" fixes. Your problem is with the CURRENT iBooks hyphenation algorithm. So you add in all of these SPECIFIC manual tweaks, to try to make it look "more aesthetically pleasing"... but the real problem should be geared towards the READER/DEVICE level, and complaining to iBooks to update/tweak their hyphenation algorithm!
Or heck, what if I did want to read WITHOUT hyphenation, your code will get in my way. (And I DO disable any and all hyphenation when I read, because I want to catch actual typos/errors, and not see the auto soft-hyphens all over the place).
What if I wanted to read left-aligned text, with no hyphenation (maybe it reminds me of MobileRead posts!). You enabling/disabling hyphenation with individual spans would make me angry.
