I have tested spacedesk (
https://www.spacedesk.net/), anydesk (
https://anydesk.com/it), and somewhat tried superdisplay (
https://superdisplay.app/).
For the moment I am using spacedesk over USB with my work setup (windows) as windows extended monitor, and anydesk over wireless with my personal laptop.
I found the latter to provide a better experience despite the (supposedly worse) latency over wireless, because I created an user with OS in light theme, resolution to match well the boox screen format, and screen mirror (isntead of screen extension).
Superdisplay is said to have better latency, but I could only test it with my boox poke4lite, and it did not seem to work correctly: I did see a mouse pointer move with low latency, but windows were not there.