@Dane,
I realise you may be suggesting this for the console itself, but I just wanted to point out that this is already possible with SQ-MixPad.
Many users take advantage of the 3 possible instances of SQ-MixPad for exactly this, with one or two devices for mixing and another just for metering (and backup!).
The ‘Custom’ layers are independent on each device/instance so you would just need to assign the channel strips you want to a custom layer and then select that layer in the ‘Meters’ screen.
Thanks,
Keith.