Like you, I don't mix with headphones. However, I do like to use headphones occasionally to solo a channel. So, I connect the headphones out to a IEM transmitter, and plug my headphones into the receiver. By default, nothing gets routed to the headphone jack. However, when you solo a channel, that goes to the headphone out. I don't believe you can route an aux send to the headphone jack. I don't see that as an option in MF.