Not a big deal, but it would be nice if it were possible.

I use an ARC controller, and the big wheel is my favorite method of adjusting the listening level. Now I have a setup for which, to listen on headphones, I use (alternatively) either the interface's headphone out or the mains out (that is to say, the headphone out of a monitor controller fed by the interface mains out). So the level is controlled by the fader position of either then mains (analog 1/2) or the phones fader.

I can obviously assign the ARC wheel to control either the mains or the phone output,  but the result is that when I use the "other" method I need to open Totalmix and move the fader with the mouse, which is slightly annoying.

Most of the times I'd simply have the wheel move both faders (maybe in a "relative" way, i.e. preserving the level difference.

Is that an option?