I very carefully rewatched the Whistling Wings video, and then saw this one too:
It starts out briefly a bit rough, but then he explains better than anybody else the "Setting the initial Servo AF position" options. For me, setting to option
1 along with using AF Case optioin
2 modified to have Tracking Sensitivity down to
0, and also setting "Switching tracked subjects" to
0 results in the best lock and fastest tracking response I've seen yet. On any camera ever! Amazing! Like some secret military weapon tech!
Summary: When Eye AF is engaged, for fast action involving people, I have AF Case 2 modified so that tracking is zero, and, on the next page of options, "Switching tracked subjects" also set to zero. Works great for me!
But when subject is really running and stopping and jumping, dodging, etc., I go with the "Expand AF area" and do my best using touch and drag to keep the subject framed properly. Otherwise, more consistent, predictable fast movement seems to be handled fine by tracking.