I forgot you said that. I've done the restore with everything, and with everything except the kepub and images directory. It works, but can get some strange effects. Opening a kepub if they aren't restored will give an error, but doing a power off and restart will normally solve this.
But, I generally don't bother at all. After a factory reset, kepubs come down from the server. And I sideload the epubs from calibre. For kepubs, I take it as an opportunity to prune the books on the device. The only issue is the reading status, and that's easy enough to solve