I just released an update to the book (notification will be going out in a couple of weeks, as I’m off on vacation) but it doesn’t cover these things yet. But I can see them being a good addition to the website.
I guess it would be both. A new widget for PyQt6 and added documentation for it’s use in the latest version of your book.
Originally I started with kivy / kivyMD but dropped it when I found a problem with the python debugger stepping code and their documentation was terrible.
I found PyQt6 to be very stable and with your help (book and website) I was able to finish an App I was working on. The only thing I missed having was a Scrolling Container (kivy has this) that widgets can be added to provide scrolling capabilities (grids, lists) on touch screens. Not sure how big a change this would be and again this would be a wish list item.