Struggling to get my Keyboard Maestro macros to open up my apps on my external monitor when it’s plugged in to my laptop. Digging through the forums it seemed like a lot of work to try to do this programmatically. Being lazy, I looked for an alternate solution and found it under System Settings->Display->Arrange..

By dragging the menu bar from my laptop screen to the top of the primary display, as shown above, my Keyboard Maestro macros now open my apps on my external display instead of my laptop.