[I've never tried the Mackie C4, but I've drooled over the description on several occasions.]
Right now we don't provide this, and the best we do is button groups (or multiswitch), see here.
The initial idea, and I still think it's not a bad one, was to eventually let you hide the buttons and show the labels on the knob/slider somehow. I still think that this idea is viable.
You might say, "wow that is cumbersome" but it's creating button groups that is cumbersome. So if I solve that problem, then this idea could fly too.
Thanks for your suggestion and for your patience as I get on to all these features.