Nikon Canada had an online "Z9 discussion" with wildlife photographer Brad Hill last night. One thing I found very interesting (because I used to overly fret about my settings in this regard on the D6) is that Chris Ogenek of Nikon Canada referred to the users manual re focus tracking and lock-on and concluded that the manual says, and what his experience has been (and Brad Hill agreed), is that when using subject detection AF modes, focus tracking with lock-on (blocked shot, and subject motion) was not involved; that is it defaults to "3" or the camera's algorithms are simply making the decisions based on subject. Some on the call did say they had noticed a difference in choosing quicker or more delayed response... Chris says he's asked Japan for clarification, though, again, his reading of the manual is there is no user chosen adjustments to be made re focus tracking and lock on when using subject detect AF modes.