I have a hot key bound to Avitab on my keyboard and I use it with some success. The problem is when Avitab opens up the image in my Oculus Quest 2 is really big, so I just grab the bottom edge to make it smaller, I can then use my mouse to do anything in Avitab, in VR, every time I open it I have to resize it this way unfortunately.
On the same subject. I also have the Aerobask Eclipse 550 and it has it's own tablet with Avitab on it. I am able to do everything on this tablet including using Avitab and Navigraph, everything works without having to use any pop up window, I don't know how Aerobask did it(or Avitab) it just works great. The Aerobask Eclipse is the only one that works for me this way though.