To use BFD2 on my Macbook Retina and still get system audio, I had to install a USB audio device (Roland MK2 Duo). That's because ASIO won't allow the system and BFD2 to use the same WDM device at the same time. I've also started using Kontakt 5's drummers, and ASIO requires Kontakt, BFD, and the system to each have exclusive control over their WDM device.
I guess I can add yet another physical USB audio device, but is there any other, perhaps more convenient way? Is there a way to enable BFD and Kontakt to share the same ASIO out? If I add a third physical audio out, I'll have to add a mixer because my monitors only have two simultaneously usable inputs.