Long story short, since a DIY kindle USB audio adapter can be made from
a regular USB OTG cable + USB audio adapter, I believe that any kindle supporting the USB audio adapter(PW3 as well as
KV KOA) should have OTG compatible hardware.
So I compiled necessary USB mouse modules from PW3 5.8.1 source and wrote a small app to monitor the mouse click and turn page accordingly.
To install, download and extract the content to /mnt/us/extensions, plug in the OTG cable and USB mouse then start from KUAL menu. To stop, remove the OTG cable first then stop from KUAL.
Configuration is in bin/config.sh which detects kindle model automatically. By default, left click/scroll wheel down = next page, right click/wheel up = previous page, middle click = menu(top area)
Other thoughts
Is it possible to add the mouse entry to /etc/xorg.conf?
and would be great if someone can build a KUAL extension so it can be installed and run without usbnet.
Supported Devices
Works on my PW3 5.8.1 and 5.8.2.
Also confirmed to work on KV and KOA 5.8.1, 5.8.2 is untested on these two yet.
On KOA battery case must be attached.
Need some test on PW2 and KT2, maybe KT3.