I'm using Rogue Amoeba Soundsource 4 for keyboard volume control but this app and any other 3rd party app for volume control is changing the volume before it gets to the audio interface, so Digicheck won't show accurate reading.

The only way to get it right is by using the interface's output fader to lower the volume but it can be done with mouse only and not keyboard.

The Fireface 802 doesn't have a knob on the front for volume control so I don't know how the ones who connecting their studio monitors directly to the 802 can use it as a monitor controller but even though I personally have a dedicated monitor controller, it is there mainly for safety so my monitors won't get full volume by accident from the audio interface but I've always used the keyboard for volume control.

On Totalmix I see ARC and key command settings.
I can make F4 key for example DIM (Main Out) and other options but why there is no way to make the F10, F11, F12 for Mute, Volume Down and Volume Up?

I'm sure many have requested this feature before, is it technically impossible for RME to add to the ARC and Function Keys menu the option to mute and changing the main out volume?