My point is that what constitutes "late" is a function of the speed of traffic. If you define "late" as "the latest point at which you can safely merge without

My point is that what constitutes "late" is a function of the speed of traffic. If you define "late" as "the latest point at which you can safely merge without causing negative traffic reactions (e.g. by forcing someone to brake)" then zipper/late merging is better than "moving over as soon as you can", even in light traffic.