Hello,
User manual for 1.9.0 can be found here :
https://drive.google.com/open?id=1kp...uhgGENH-IM_qDx
for Max2, but it probably applies also to Note for most features.
The Onyx download page is here :
http://www.boox.com/downloads/
and it contains the firmware and manual for 1.9.0 (and 1.8 for Max)