alt Hacker News> Not necessarily? There was a post just a year ago on how somebody jailbroke the kindle books from the web UI.
I used that research to build something similar. It only works for manga and comics right now, but I have been tinkering with implementing glyph support as well to be able to handle full books.
https://github.com/Alexia/kandle-downloader
The original research is here, but the web site is down right now. https://blog.pixelmelt.dev/kindle-web-drm/
Probably not the best place to ping for technical support, but, since you claim to be the author, and I don't see any "Issues" on your GH...
Any idea why your script does not seem to flag as a valid greasemonkey script when I try to use it in the Falkon (KDE) browser? Even if I attempt to add it manually, the script then disappears from my gm scripts.