I have a 3 Monitor plus 1 Projector set up. I set the projector to mirror one of my 3 monitors, but would like to dim the three monitors whenever I want to play something on the projector. The Dim Specific Monitors function by Thomas Malloch works great, but the issue is I cannot dim ONLY the 3 monitors since the projector is mirrored to one of them and gets dimmed as well.

Setting the projector as a separate screen raises the issue of having windows trapped on the projector screen that I'm unaware of (the PC still recognizes the projector as a 4th screen even when it's turned off). Additionally, my projector screen is behind me so it's hard to manipulate windows and maneuver the mouse while having to look directly behind.

Is there a way to dim just one of the two mirrored monitors?

Thats unfortunate. Thanks for answering!