Limit trigger to display sleep

Hey guys, I can have triggers that work even when the Mac is in "display sleep" state. That's cool. But can I have gestures that are limited to this state?

I often hear music via the Mac but want all displays to be asleep. Now I want a gesture on my Magic Mouse to change the volume. Currently I use the Pinch-Gesture. But a simple scrolling would be better.

I think this can be achieved by adding an extra action after the volume control action to put the display back to sleep.

This has an obvious issue, however, that during normal operations, it would also put the display to sleep every time you change the volume.

A workaround for that would be to set a variable whenever the display goes to sleep and then check its state before the second action following the volume control activates. So, if display was asleep when volume modified, sleep display immediately after, otherwise just modify volume.