You're working with too many unknowns.
You can attack this from either side.
Preliminaries: Start with a fresh boot and don't touch the KOReader at all.
Turn on Onyx auto rotate.
Install and run UsbMode.apk in
http://www.temblast.com/usbmode.htm
Hold the Leaf2 in your right hand, press the A, then the B, note what happens.
Hold the Leaf2 in your left hand, press the A, then the B, note what happens.
See diagram. The A button is always the same physical button. Likewise B.