Not to sidetrack the thread but it is interesting to look at a thread from 4 years ago this month to see what people wanted.
https://www.mobileread.com/forums/showthread.php?t=5843
It was focused on E-Ink when there were only 4 current devices and other 2 were available outside of Asia, the Sony PRS500 and the iRex iLiad. The other two were Jinke devices, the V8 and V2. At that point the original Sony Libre had be discontinued. The wiki reader matrix of the day showed 4 devices.
Dale