Desktop notifications setting: Only if I launch app.

Notifications on Desktop occur whether or not I have the app open.  There is no way (I can see) to only have notifications when I choose to open the App.

This frustrates me to no end on the gaming PC since it will ring notifications, stealing them from other platforms - and if I shut off notifications, it doesn't seem to be just that particular platform or until the next launch. Even calls will get stuck and I can't answer them, because that windows machine has stolen them from all other machines - silently, in the background.  No app badges, nothing in the message center.

I use it for fullscreen and VR gaming and the notifications just get lost!

i want to just turn off notifications while the app is closed, and only on that PC.  Is that so hard for it to behave?