Approach Angle is the setting you need to lower to make line acquisition slower/ less aggressive. Lower this and you should see improvement.

Steering Aggressiveness is the overall system aggressiveness adjustment. It won’t do much for line acquisition.

My Z2 steered 4wd and a bunch of other 4wd drive tractors I have put them in steer great and acquire the next line smoothly from 90 or so degrees through the headland turn.

This sounds like an issue should be able to solve through tuning/settings adjustments.