Brian -
Maximum lag will not always produce maximum distance. Maybe maximum clubhead speed, but not maximum distance. Centerness of hit and spin loft (which is greatly affected by attack angle) come into play.
How about of video discussing where lag really is and if it can be measured/calculated. If often feel what I call lag on the downswing and I'm not sure that is the same lag that you're discussing which I think is forward shaft lean/dynamic loft for a given shot.