I use a Nikon D850 an invariably use manual exposure and auto ISO and continuous AF servo (with back button focus). My Fn1 button switches to 9 point AF mode which is ideal if a bird suddenly takes flight, you can switch focus mode with your camera raised to your eye.

Greetings,

Yes, holding focus on objects heading towards the lens is the most challenging. How successful you are will depend on the optics and the design of the auto focus electronics.

Actions you can take to improve your odds are:
· Always shoot with the fastest shutter speed your camera and your tolerance for a higher ISO settings allow.
· Make sure you are using the most recent camera firmware
· Search on-line for the camera settings that will optimize your camera and lens for best tracking results
· If you have questions contact the manufactures customer support to get their recommendations
· You may find that your camera provides the best tracking using the center focus points, if so stick with those, this may mean you zoom out a bit, but a little cropping is worth a sharp focus.
· If your camera system has the capability for micro-focus lens calibration run the protocol with your camera and lens.
micro focus adjustment

Happy Shooting!

Steve
Outdoor Photography Guide