Should not have a 6 to 10 second lag, not sure why that would be happening. To OP, what are you shooting for stills. landscapes, or close ups? Reason I ask, once the M2 Pro has focused on an object in the distance it's in focus. I shoot thousands of stills, (all I shoot, no video), and never have had any issues, I always shoot in 5 shot brackets also. Once I acquire focus (using AF and hitting a spot on the screen) I quickly shift back to MF, and shoot the rest of the shoots, and in fact, hardly ever check again. You can turn on focus peaking, so that when you switch back from AF to MF, you will see the peaking. If you see peaking on objects out in the distance, you are in focus. The hyperlocal distance on the lens, is minimal. Unless you are trying to focus on something say 10 feet or closer, I would hit AF, Move to MF and see if you still have lag. If you are shooting longer exposures, 1 second or longer, you might get slight lag, but even that is not common. Also if you are on AFC, I would take if off as AFC can create problems (drone trying to acquire focus on dark areas, or sky, it will hunt and that can create lag).
The shutter for me on 3 M2 Pro's is quick and really actuates as soon as I hit the button on the
SC screen.
Paul C