Originally Posted by theducks
That setting is only for EPUB=>EPUB or MOBI=>MOBI
Hmmm. Really? I guess that makes sense, although I'd love an option to preserve a pristine copy of whatever format you originally imported the book in. After all, information IS lost in conversion, and there's no way to get it back if you don't have a copy of the original.
(Yes, I keep backups. Still.)