It looks like some clever coders have figured out how to remove DRM from newer Kindle books now. It’s a bit more of an involved process than previously, but totally doable - only if of course it is legal where you live!

You will need version 2.8ish of Kindle for Windows (which is the current version at the time of writing), Calibre and a couple of Calibre addins installed:

• DeDrm version 10.0.15 (at least that’s the current one that works)
• A recent version of KFX input, which you can get from Calibre’s inbuilt “Get new plugins” feature. I am on version 2.28.0.

The DeDrm plugin needs a bit of configuring before it will work. I will likely do a proper writeup soon, but for now, following “solution 1” here should work.