I confirm that with the stock firmware (v2.1 ?) nothing worked with Linux laptops. But I tried it with a laptop with Win7 (still at v2.1) it was working - apparently it was confirmed by Onyx.
When applying the update (today still v2.2 available for me, the one of the 6th of September), it suddenly worked on Linux, more precisely I have a Acer SF113-31 on Mint XFCE 19.2 kernel 4.15.
Though - of course I need to put it on ‘speed’ or ‘X’ mode to see something. It remains hard to follow the movement of the mouse. And the screen is so big it makes it hard to read -
But I suggest on Linux the following changes, seen on some forums, i.e. type:
to see on which ‘screen’ is connected the Max3 : on my case “eDP-1” was the native screen and “HDMI-1” the Max3
and then type:
$ xrandr --output HDMI-1 --auto --scale .5x.5
It will reduce the definition to half, something netbook-like, but much more visible - and I must say quite acceptable for things like typing, maybe chatting or something quiet (without use of click of mouse).