I actually reached out direct to Inibuilds about this matter. I will say, they have been great at replying and sending information. Clearly, it works on other aircraft, so I suspect that’s the way Inibuilds have made this great aircraft, without this function. The last I heard back was a few days ago, I’ll paste the response I got below so I don’t misspeak as to what they said, but I think this is where we are with it….
“I've spoke to the team and they have said that this isn't currently supported in the sim as the mouse events aren't transmitted back to the sim on the popout screens.”