Recently I have been combining C-AF with High continuous. This seem to provide an interesting operation where the camera continuously focuses at half press while I follow the subject, and than locks on when I trip the shutter. I have been using this with some success with my E-M5 III that does 30fps at high burst. I actually have a better keeper rate sometimes than with C-AF and low continuous with my E-M1 II.One thing to remember about C-AF, is that the camera will fire, even if the lens has not reached focus.
Example when I shoot volleyball, I will quickly shift players from A to B and FIRE. The lens is still changing focus from A to B when I fire the first shot, and the odd are that shot #1 will be OOF. Shot #2 is usually in focus, as the lens has finally caught up and has subject B in focus.
I don't use BBF. For me, it is not worth the hassle of changing.
I may change my mind later.
You need to RTFM on YOUR camera, because it can be/is confusing. It was for me.
Continuous Low and continuous High may behave different on your camera.
On my camera Low will AF on EACH frame in a burst.But High will focus on frame one, then lock focus, so every shot after that will be focused at the same distance as frame one. So if the subject moves closer or farther, it will be OOF.On another camera, High will AF for each frame, but ONLY at 9fps. At 10fps, it would lock focus on frame 1. Did I mention it is confusing.And mechanical and electronic shutters may behave different, so again RTFM.
Try the various AF area modes, to see which works for your and your specific subjects.
Example 99+% of the time I use fixed single point, it is only for singles tennis that I use 3x3 area mode. Every other sport, other players are too close to my subject to use area mode.But a single child or dog, area might work well for you. You have to try it to determine what works best for YOU.