I just did some reading on Amazon and they say they have over 1 million books in Kindle Unlimited. They said there were thousands of books in Prime lending and they say the KOLL books can be identified because they have a Prime reading badge. I'm a bit confused about the different plans. I had thought that Prime lending and KOLL were the same thing and Amazon does seem to indicate that but not clearly and other sites and mentions in this forum seem to indicate that they're different.
I also just tried converting a Kindle Unlimited book to an epub with Calibre and Apprentice Alf. It worked just fine. I thought that might be a fluke so I tried another one, which also worked. It does seem they can be converted just like any other book.
I would recommend doing this on any kind of regular basis. I suspect that Amazon will know since in effect I "read' the entire book in a few seconds. I'm assuming here that Calibre uses Kindle for PC as part of it's conversion process. If it doesn't will someone let me know?
I did delete the books after testing them so please don't ban me.
Wait. There shouldn't have been a smiley. I've been banned for such things in the past.
Barry