22/08/23 19:52:20.58 DSUDXfEY.net
FILEFORMATサイトによれば、
KFXはa complex format as it combines several different features of Kindle File Formatsであって、
KFXフォーマットは
･soft-hyphens using a new enhanced typesetting engine
･a new image file format called JXR, which has a higher compression ratio
･the new Bookerly font which is Kindle-exclusive font providing improved readability on digital devices.
･multi-page thumbnails, content auto-adjustment around images and videos at fixed locations
をサポートしてるとのこと
KFXを回避してダウンしたらそりゃ機能的に下位互換な電子書籍になるわな