QU16 send to usb post-faders

Hello, this is my first time posting here.
I hope I’m not missing something obvious. But I can not determine how to send to USB post fader. Pre fader is working perfectly.

If this isn’t possible, can I send the mixed audio back to one of the mixes so that I can mix the output per channel? For example, if I want to change the vocal mic, I can continue to do that with faders.

My situation is:
I’m sending the audio to Mainstage on a Mac where I’m applying some effects, IR’s etc.
I then send this audio back to the desk on Output 21 / 22. So ST3 on the desk.

This works fine pre-fader. I really want to be able to mix the volumes, EQ’s etc directly on the desk. It’s interface is far better than that in Mainstage.

Again, sorry if I’m missing something very straight forward. I’m blind. So I’m currently reading the manual then asking my wife ( very nicely) to navigate through the menus.

Recommendations and suggestions very welcome and very appreciated.

Thanks

I don’t have a QU, but I found the following in the manual, which could possibly solve your problem:
In the Direct Out settings you will find 5 source points where you can get the signals, but also an option to follow the faders (see also picture).

It’s wonderful that you are such a team: your wife can see better, but you can certainly hear much better. )
All the best to you both!