Based on the results of test 3 – I tried AF Tracking Large. When shooting the ducks in the harbour I found this to be slow to acquire focus and went back to Expand Flexible Spot as the alternate focus mode. The default focus mode remained Zone.
As well AF Tracking Sensitivity was set to 4.
It looks like the settings are pretty well stabilizing for the harbour – I suspect Florida and small birds in trees will have variations of these settings.