I am on the fence about buying a CQ-20B, but if the alt out and headphone out could have their own stereo mixes (for IEMs in my case), this would basically be an insta-buy for me. I also would be splitting the inputs for FOH, freeing up the Main LR for another stereo IEM mix, which would give a total of 6 independent stereo IEM mixes in total if this could be done.
Or maybe this can’t be done directly but there are workarounds if anyone would know? I know some other mixers can do some fx routing trickery to add an extra mix.