I have just added a Mackie MCU Extender (XT Pro) to my existing MCU Pro control surface. Setup went fine but I have found an anomaly:
Per the Steinberg documentation for the MCU Pro / XT Pro pressing Shift+Project changes the behaviour of the solo buttons to toggle Listen Mode for each channel. However, this only works on the MCU Pro main unit; the solo buttons on the extender continue to toggle the Solo state.
I have checked the consistency of other functions between the two units and have not found any other anomalies.
Has anyone else detected this issue?