Agree with startergo that even if BCA can be used, it shouldn't be at this point. Mainly because co-locating Windows and macOS on the same physical drive is just a bad idea in general. I get that it's often necessary in MacBooks and other Macs with only one internal drive. But with internal storage being cheap and plentiful on the cMP you are so much better off just dedicating a SATA drive to Windows.