@QLE
The SQ has a 32×32 channel USB interface.
You can freely route any SQ channels to USB using the ‘I/O > Outputs’ screen by selecting ‘USB’ at the top of the patching grid then choosing an output on the left hand side (direct outs, mix outs, rack FX or monitor outs).
It’s also possible to route any of the 32 returning signals from USB to input channels or mix external inputs using the ‘I/O > Inputs’ screen.
By default, returning channels 1&2 are patched to stereo input processing channel 47&48 which is also labelled ‘USB’.
Also by default, the LR mix is patched to USB outputs 1&2 (so it’s quick and easy to make a stereo recording), and direct outs 3-32 are patched to matching USB outputs.
So to send a custom mix (an Aux) to USB 1&2, you just need to patch that Aux to the USB output sockets you’re recording in Logic using the ‘I/O > Outputs > Mix Out’ screen with USB output sockets selected at the top.
Check out the reference guide for more info – https://www.allen-heath.com/media/SQ_ReferenceGuide_V1_5_0.pdf#page=18&zoom=auto,-361,573
Cheers,
Keith.