@Brad
You could just route a prefade Aux mix to Main L/R and set up the senior citizens that way via SQ4YOU.
Or let them use mixpad and set their one mic and PC input on a custom layer. As long as they can find the custom layer, all good.
@nottooloud
If implemented, you would want some feature to lock out band members from accessing the L/R Main. There’s nothing worse than seeing your FOH faders magically move in front of you when another user is supposedly adjusting the online mix but accidentally are on the wrong mix (as happens frequently with Mixpad in our church!). If you are doing a walk around is there still the need for the overview / metering tablet at that time, or can you just use that?