CLS will not recognize multiple speedlights in a given group illuminating the subject because they all fire at the same time during preflash sequence. CLS will return the same exposure compensation value (within the + or - three stop limits) to all units in that given group.
CLS will not recognize if speedlights in a different group will overlap with units in other groups because their preflash sequences occur at different times. Should units in multiple groups overlap, they will be additive, overexposure should result and the photographer will have to enter negative exposure compensation values for appropriate groups in the on-camera master/commander.
Remember, CLS has no idea how many speedlights are configured in each group and where they are all pointed.
Russ's test confirms this. Thanks Russ!
Edited to correct missing word in first sentence: "not".
Regards, HBB in Phoenix, Arizona Nikonian Team Member
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