Hi !
Have a look at here, it should answer your questions ;o)
Scroll down the page to my first answer in the thread.
I used this with a BCF 2000 and then an iCON QCon Pro (and it also works perfectly with an MCU)
For this trick to work on the master, you’ll have to add a second GR peripheral and set it up so that when pressing “Master”, it selects the master in Cubase. Once you have finished recording and you are mixing, just reconfigure this second GR to select the Master Channel (that is because when you add track to your project, the GR shifts tracks).
Cheers.