[tomsem]

There are a number of fixed layout formats Kindles support.

Print Replica is the most analogous to PDF, and is in fact what Scribe and Kindle Colorsoft (and the Kindle apps) get when you send a PDF to Send To Kindle. I have no idea why the others do not get them as well (they get PDF, which does not sync annotations and reading position), you can certainly side-load them and they will open and render 'as expected' on any recent Kindle.

The main issue is that there is no 2 page display, whatever size display you have. It's a huge weakness of the ecosystem, as PDF is the only fixed layout format that Send To Kindle supports. Fixed layout ePub gives conversion error and yields AZW3 with inconsistent behavior on different Kindles and Kindle apps.

The other fixed layout formats (comics/manga/children) can be read on any Kindle, and can support 2 page display even on 6" displays.

There's one KFX format that is more like fixed-layout ePub, with all of its many warts. I do not know how you create them. Kindle Create (which can produce all of the other KFX variants for KDP) will not ingest fixed-layout ePub. So it must involve some internal tool. I have seen it used for 'coffee table books' with complex layout and text. But text is not interactive: you cannot select or highlight or even do text search (that is true of FXL ePub too on most platforms). It's ludicrous that even B&W 6" Kindles can get these, but at least you can if you want to suffer.

Print Replica is commonly used for textbooks in Kindle format (math/engineering/techinical). These also cost a lot more, and publishers tend to restrict it to the apps which have strongest DRM measures (Apple/Android - though Windows remains 'in play' for a bit longer).

Amazon's recent and more aggressive efforts to harden Kindle DRM (and cut off older devices) may be laying the groundwork for the day when these textbooks will be available at least for Scribe lineup, which has a large enough display to make it workable.

But will textbook publishers embrace it? It is ultimately their choice.

Amazon would most likely need to restrict annotation that's available for print replica personal documents: just highlights and text notes, and maybe no drawing.

Currently you can export notes to PDF, and full page page previews are included for pages with drawing on them. And you can export the entire document with drawing and highlights overlaid. Either would provide a way to casually share content of the textbook with people who cannot afford to purchase (or even rent).

If drawing annotation weren't allowed in the first place then it would be on par with Kindle apps in terms of 'sharing'. But Kindle apps allow copy and paste (to other apps) without restriction AFAICT. Not to mention screen captures (also possible on Kindles).

There are a few dozen at least 'Open Access' books in Print Replica that are free. I think there is perhaps one that allowed download to Scribe but no idea how to discover it again. You would think they'd think a little and enable download to Scribe, since no profits are at stake. But no.

Apart from that there are the Write On Books: puzzle or journalling books, only available for Scribe (and easy to find or create in PDF for free).