Within the configuration setting i can see both monitor outputs but only able to sync one HDMI at a time. anyway to configure both (HDMI) and (HDMI 3)?
I believe that you can only choose one HDMI output at a time. I realize you were asking about auto switching between apps, but I don't believe this is a function that Linux has, but I could be wrong.
What I thought you would find useful however, was the ability to choose your output, and the ability to adjust the individual volumes of each app that is currently playing sound, its a very useful feature.
Unless I am mistaken, I think that Pulse Audio is the most powerful utility for sound. You can also install the Pulse Effects APP, which adds great functionality to you, you might like that one too.
And you can also get a sound output chooser extension to allow you to choose input/output settings and volumes from your taskbar too.
Thanks for your help all, can see that Linux doesn't like dual HDMI outputs like windows. Can switch between them i guess.
After a few hours playing around managed to get my sound card (Sound Blaster Z) working with speakers and headphones after installing Alsamixer to enable headphones.