There is another way to read Kindle books without using Calibre to convert the books to epub. A member of this forum developed a program called "lcd2eink" that enables you to view the page on your lcd on the eink side. Here is the link to that discussion. It provides directions.
https://www.mobileread.com/forums/sho...light=lcd2eink
With lcd2eink enabled, I can open a Kindle book in the Kindle app on the lcd side and read the book on the eink side. I use the stylus on the eink side to turn the pages. All the while, th book is opened on the lcd side even though the lcd screen is turned off.