Hear hear ! I would also like the ability to use a fader port or equivalent.
In essence use a 32R with an Ipad roaming, or a FOH MacOs UC with faderport(s) mapped to channels/mixes.
something like a 16 for inputs and an 8 wide for mixes would be powerful add ons, giving the intuitive feel that a touch screen lacks
For what it's worth, the esteemed "X" competition seems to be able to do this.