I prefer to run MSFS in Full Screen - it’s a bit faster and more immersive, in my opinion.
But there is a bit of a problem. When you run in Full Screen, you lose all access to any apps as icons on your Windows desktop, Start Menu or Taskbar.
If, for example, I’m running MSFS and I would like to have a moving map that’s a bit better than the built-in VFR Map, I could start VFRMap and Chrome, or I could start FSTramp. Those apps are on my Desktop, but I can’t get to the Desktop without pausing the sim and going to Windowed Mode.
I have found one way to access my MSFS apps in mid-flight, even in Windowed Mode.
And I am wondering if you know of any other ways of accessing MSFS-associated programs from within MSFS?
My solution is an old, obscure Windows application, “Hidden Menu”. It can be popped up in a corner of the MSFS screen with a list of your favourite programs.
You don’t actually have to stop the simulation: in windows 10 even in full screen mode by tapping the “windows” keyboard key, or alt-tab brings up any other application window, while the sim is running. Not perfect but you can look up a chart or a map in a window as long as you keep focus on that. Not perfect but …
If the companion app is already started, there’s no problem switching to it with Alt-Tab.
But how do you start the desired app from its icon if MSFS is running in Full Screen mode?
A pop-up menu is the answer - but most such menus have to be activated from the Start menu or the Task Bar. “Hidden Menu” pops up from the screen corner, even in Full Screen mode.
You can use little nav map on another computer and connect the app through the network. It works flawlessly. I understand you did not ask for this solution, but maybe the piece of information might be valuable for you.