Case 1: Default tracking for general subjects.
Case 2: Continues to track subject with intermittent obstacles blocking subject.
Case 3: You can think of this as the opposite of Case 2. Instantly tracks new subjects entering the frame.
Case 4: Good for subjects that are abruptly accelerating or decelerating. Not to sure this is useful for weddings, but if you were shooting sports such as tracking a basketball being passed I’d imagine this would be useful.
Case 5: For erratic subject movement. Might be useful at a skeet shooting themed wedding I suppose.
Case 6: Useful if you are shooting multiple skeet shooting themed weddings simultaneously.