As described in the manuals, Aviator uses by default standard datarefs for all of the aircraft.
Some developers ( E-Jets can be the case) use custom datarefs to set the values of the instruments.
Aviator Pro allows users to define custom datarefs for specific aircraft, but this is not a task for non advanced users.
Some users share custom definitions in the X-Plane Org forums, as you can see no one uses this forum for Aviator, just for SkyElite which is for MSFS.
Check this file in Aviator Pro documentation: "Aviator - Custom Switch Panel.pdf"
There are also examples of customization for other aircraft.