Is there another way to assign mute-groups on the Series III console other than holding down the user button when ONLY the desired channels are muted? This is fine if the groups never change and can be set once, however, it is difficult if not impossible to modify a group during a rehearsal/sound check/performance for the following reasons:
1) It requires visiting at least 4 or 5 different layers/sub-layers (Inputs, Mixes, FXs, etc.) to mute every channel included in the new group and unmute every channel NOT included in the new group.
2) Due to #1, the specific mute and unmute combination determines the makeup of each mix and this rarely corresponds to what the current live situation requires.
To overcome the above issues, I suggest adding a screen that works similar to DCA assignment to select which channels participate in each mute group.
Also, once a channel has been muted individually, the mute group cannot "regain" control of that channel's mute state and will not unmute it along with the rest of the channels in that group. I suggest operation similar to the DCA mutes, which can override individual channel mute states (once it requires toggling).