External Monitoring

Would be ideal if you could simultaneously run Resolve and Fusion and have the external monitor switch as you switch applications.

It does.

If you have a Decklink, or a Ultrastudio, you can.
The monitor out of each program takes control as you switch back and forth.

Is there a setting in Resolve for this because for v11 and v12 on my System with a Decklink Extreme 4k it just grabs a hold of the output and won't let go. Switching between AE/FCPX/Premiere/Fusion are all fine...