I've settled on Release + Focus. Bang off that first one even if focus hasn't had time to fully achieve, in hopes that it may have gotten close enough to achieve a usable image. But at least get something and get it quick. It might be the only shot I get. Because the first shot might be my only chance, my intuition tells me to only select from modes that start with the word Release.
+ Focus for the rest of the burst because personally I don't need a whole series where focus was not achieved, so I'll trade a possibly slower burst for better quality. The theory is also that by second frame, the camera has had plenty of time to achieve focus, so I'm not giving up much by waiting for the focus system.
If I was a PJ who has to get the shot, I'd probably just go with pure Release. Same if I am doing extreme high speed action.
But some of my event work, maybe I should consider Focus. I guess one could make use of any of the modes, depending on setting.