I think the 350f has contours from the factory, too.
I just looked at my 350F and it does have indentations (obviously factory-pressed, they're a distinct shape) on the back of the headlamp ears, but I don't think they're for tank clearance. Even at full lock there's an easy 3/4" between the tank and the ears, so I don't think that's what they're for. My guess is the indentation is to squeeze down the fork ear so it sits correctly against the inner fork tube.