Speaking of Logos... In the 2015 thread we had a discussion about the ability to send Logos/Vyrso books to your Kindle. Logos is retiring that feature at the end of March (See
https://community.logos.com/forums/t/123765.aspx).
After that, you are back to the workaround people used before Logos offered that feature. The Logos desktop app actually lets you export up to 100 pages of a book in one go. If you set it to the biggest page size possible, most books can be completely exported in only a few steps. Search the Logos forums for more instructions.