The pros are different animals. They are not like you and I. I don't think ordinary mortals can adopt pro technique and expect to get better results from it. Hammering the downstroke is definitely more efficient, but how long can we do that without tiring the fewer muscles involved? Being a wimp, I get better endurance by spreading the stress out over as many muscles as possible, while still hammering that downstroke when I need to. Notably, I think TTers of all abilities mostly hammer the downstroke, but that's only for an hour, which is nothing for an endurance rider. The smaller the percentage of max muscle force we exert, the longer we last, i.e. the fewer type 2 fibers we recruit.