Hi,
Not sure about whether this behaviour is diff related or weight-distribution related, but I've noticed something like this on my M135i auto.
I posted a while back about a sensation similar to
torque steer at full throttle.
I imagine the tilt of engine on its soft mounts could make the car temporarily heaver on the right hand side because of the longitudial mounting arrangement. Or at least the engine rock could feel a little like that through the steering wheel anyway.