Hi - new here. Just got a SQ RACK and one of the reason I got it is for the SQ Control button/screen. I do some work for a community hall and liked the idea of setting up the SQ Control screen and then locking down everything else so no curious people can adjust things. It seems that unless you set gain on the fader there is no way to adjust it on the control screen if the faders are locked. Did I miss this or is this not a feature?