I have two back focus buttons set up and disabled AF ON on the shutter button.
One button is set up for Whole Area subject detection and tracking which is what I use 99% of the time. The R7
is quick to detect any animal/bird in the frame - usually I will center the subject for the initial
AF ON, Whole Area AF, Animal, Eye AF ON, Tracking ON
AF ON + Single Point AF, Animal, Eye AF ON, Tracking ON
If you have trouble with focus drifting on small birds close the busy backgrounds or near the ground try using spot
focus with no tracking