Please consider adding this feature. I just recorded a band with the CQ18T, the results were great, but having the ability to monitor multiple inputs at once via the headphone output would have made the process much easier.
I use the outs of the CQ 18 to a Rane 6 channel headphone amp.
Still working it out but I think this will work.
Using it with LPX and I use the send on each channel and set the send to output 3 into the Rane HP amp (6 channels). You can also add additional send i.e output 4-5-6 and have up to 4 HP mixes. Still working out if I can use CQ outs 1+2 because LPX defaults to 1+2.