On the issue of having to repeat all the steps. I use an AutoHotKey script to save some leg work. I've attached the script I use. Once I have FSXSE running in free flight maximized but not in full screen mode I click Control-M and then wait for the script to finish without touching the mouse. My script is for 3 secondary monitors in a row above my laptop. If your setup is different, you'd need to edit the script to suit. The delays in the script work for my laptop but might need adjustment for other rigs. You end up with four windows with title bars removed so it looks like Fullscreen but isn't.
FSXSE Multi-monitor.zip
