Hello everyone, I hope I can explain myself well.
I have a QU-SB and I would like to know if, by purchasing the QU-16, could I use the SB as if it were an AR2412 expander using de dSnake port?.
No – in this case you would be trying to connect two mixers that both want to be clock leader and have no mechanism to clock to an external source.
The Qu series can only be connected system to system with an SQ (as described here – https://support.allen-heath.com/hc/en-gb/articles/4403618840849-General-How-to-connect-Qu-SQ), where the SQ can clock to the Qu.
Note that this is still a system to system connection however – although the Qu-SB looks very much like an expander, it is a mixer!