Hi Eythoralex,
The Qu-SB and Qu-Pac are both mixers and cannot be used as a stage box in the same way as a DX or AB box. You can share audio between Qu and SQ, but there is no control over the preamps from the SQ when the inputs of the Qu are used. This means that you would need to use the Qu-Pad app to make preamp adjustments on the Qu.
If you were to use an AB168 stage box with your SQ, you could also use it with a Qu-SB or Qu-Pac for events that require a smaller foot print. As this would give you 32 microphone inputs in this small setup.
Thanks!
Alex