[Tugger]

But that would mean that we have a situation where a file made by Kindlegen is a correct input to KDP, and is a correct input to Previewer but is not a correct input to an actual device. Have I got that right?

If so, could we not have a patch that would somehow alter this mobi not for upload to KDP but only for upload to a device.

If we can't do this I can't make files that will be correct on a device without uploading them and then buying them, which is madness.

So I think you are then saying that Mobi-unpack could do it, but Mobi-unpack doesn't let one end up with a mobi file. Could Mobi-unpack produce the mobi7 and mobi8 versions of the mobi file for us as well as what it produces now??