Keeping a target locked in the middle of your screen is useless if you're on the roof. In order to make that useful, you'd need to have code that calculates what you're looking at, and then keep you looking at it when you change position. This is useful for certain situations, but would create some really odd behavior when not looking at a human target. Turning auto wallwalk pitching off just means that you're looking at the floor if you start by looking at the human, and turning auto wallwalk pitching on means that the angle that you're looking at relative to the surface you're walking on is preserved, which is only what you were looking at before in very specific situations. You can set it to hit a human in the head when on the ground and keep it that way, which is useful, but you won't be seeing your target on the initial approach. So unfortunately it isn't something that really can viably happen.
