Hi, I play R3E on my TV, so I have my primary monitor and then the TV as a secondary monitor (and another one for telemetry etc) and always had the problem to assign the TV as primary monitor first before starting the game manually. All i wanted was the game to start on my secondary monitor by default but that does not seem to work without third party applications. So I found the program "UltraMon" which lets you create shortcuts with different settings. I created a shortcut for R3E, so now when I start the game (in steam, or the desktop icon) UltraMon automatically assigns my TV as primary monitor. When the game closes the monitor assignment switches back to default. I just opened this thread in case someone encountered the same problem and has not found a solution to this day. So if you want to do the same thing and maybe need help to set up a shortcut properly just leave a message here. (Of course it works with any program you like)
It works pretty flawlessly. I thought at first the program switches the monitor and after closing the game it switches back. That's not the case, it's even better. When you start the game or prgram of your liking, it switches the secondary monitor to primary. While the Game/Program starts it switches the monitors back again, but now the game stays on the secondary monitor and you have your default primary monitor again. And there's another benefit: Your game won't minimize or pause when you click around on your other monitor. You can fully use the other monitor while the other monitor shows the game/program. That was always an issue when I tried to adjust my EDTracker (sth like TrackIR but with gyroscope and no IR) on a second monitor. Now R3E leaves open.