I think he is just saying he didn't have to think about all this as BAC did all the legwork for him. Minus machining the hubs to fit his wheels anyways.
Regardless of which brake kit you run and from whom you have to consider the wheel fit- that’s true for ALL aftermarket brake kits. I had my RPF1’s hub bore machined for the hubs, but that would be the case either way since the hubs have the same diameter with all of the kits mentioned so far (they may even be the same hubs).
I didn’t have to think about where the rotors came from either. I just like to know because if DoctorDiff stops selling a certain kit I want to be able to support pad and rotor changes down the road. I would do the same if I bought a kit from BAC.