[jhowell]

Thanks for the kind words, odamizu and mattmc.

By being so secretive about the workings of KFX, Amazon has made it an interesting mystery for me. I have enjoyed delving into its secrets. For me this has been driven by academic interest, rather than any practical need.

I don't sideload books. Most of my reading material is sourced from Amazon and so already supports enhanced typesetting. The few books I purchase from other sources I send to my personal documents so that they will be synchronized across my multiple reading devices, so being able to do my own conversion to KFX for sideloading has no practical use for me.

At one time I thought that being able to convert from KFX to EPUB would be useful, but that has turned out not to be true (at least at present.) The loss of HTML internal coding during EPUB to KDF/KFX conversion makes it a less preferable format for archival or conversion when compared with KF8. Since Amazon continues to make KF8 versions of purchased books easily available it would be disadvantageous to use KFX for that purpose.

Although lacking practical utility, I will probably continue investigating KFX until I stop making progress or something else piques my interest.

Most recently I have scripted the EPUB to KDF conversion process so that it is possible to do bulk conversion. This should give me more data on the equivalence between EPUB and KDF/KFX.

If I ever get it working to my satisfaction, I plan to package the EPUB to KFX conversion process into a calibre plugin. Others may have a use for that capability.