Volume control on iMac in exclusive mode

I can see that if you use exclusive mode in core audio then the volume controls on the Mac keyboard are disabled and you have to use Roon for volume.

I think I know the answer but is there any way to get keyboard (ie F11/F12) to control the Roon slider in exclusive mode?
It’s just handy if I am working and the phone rings that I can just hit the keyboard rather than having to flick to Roon.

I am connected via USB to an Oppo HA2 direct to power amp via line out. Core is on another PC. Roon controls the Oppo volume fine via the Roon slider.

This is my first Mac so go easy on me.

Hi Steve,

Here are some keyboard shortcuts.

However, I believe that the Roon app screen needs to be active for them to work. So, you would have to maximize the app from the lower right of the screen and then press Cmd and down arrow to lower the volume.

Cheers, Greg