CloneKeeper

Once you read the above mentioned articles, and are more familiar with the options, you can set what monitor CoH uses. I have three monitors, and typically output to my center monitor so that I can have a web browser up on the right and Discord up on the left. I find playing in Windowed mode (with the Windows frames) just takes me right out of the game. If you see a borderless setting with a specified monitor, it should display at the native resolution for that monitor.