As the title say’s, can find it in 1.7.06 under device settings but not the 2.0-RC2…
What am I missing
I see the following, but it may be related to the protocol your using for your laser. MIne is the Xtool S1.
try to move your mouse over the bottom boarder of the window until it changes to an “up and down” arrow, enlarge the window 
I have the same problem as Brian
I have Sculpfun S9 with 10 watt laser…
I have no laser connected to this computer inside but the 1.7.06 isn’t either and that has the Air Assist on it so…
I’m thinking and working on getting the air assist pump working on the laser to save me not remembering to switch on and off all the time… Will start another thread when I get the parts together…
I don´t know if LightBurn output GCode to de/activate XTool Air-assist…but you can add code to the GCode tab Start GCode and End GCode.
Hello, I’m using the Xtool Protocol so the device settings may be different, as I do not have a custom Gcode tab, only Gcode, and there is no Air Assist setting, see below:
Thank you Brian
For me my air assist works, but it is always on high pressure, there is no way to have it come out at the lower pressure setting, that I can see within lightburn for the Xtool S1.
Reagrds
Brian
I will try, but air assist only goes on , when I have it enabled at the layer level and have it on. Just wanted to add that, as it is not on all the time.