I am told that Schuberth only links to Schuberth (Scala). I believe, Bluetooth allows only for 1 pairing. Using new BMW Navigator V and using BMW Blutooth, rider & passenger Schuberths are paired with the navigation.
Using Schuberth’s Blutooth, you could do two, e.g. iPhone and 1 additonal (another rider or passenger), and Schuberth would automatically disconnect one and do another – back & forth. But I never tried. I would have to take a look at Schuberth’s documentation again to understand. But then, now I am using BMW’s inside my Schuberths so there goes that idea.