NY formulated on Friday :
The delay in roadworks is often the slowing everyone to a crawl so they can
merge; once they have merged, the resulting single lane can often accelerate
again and move through the roadworks at a sensible speed for the proximity of
the workmen, rather then at a crawl. I wonder whether queues would be as bad
if traffic all merged early, without needing to slow to a zip-merge speed.

No it would not help. Once both lanes are into one lane at the official
merge point, individual vehicles will do twice the speed because the
speed before had been shared equally between the two lanes.