Very interesting discussion here. Nice to read about things I used to do (retired now after 30 Yrs of flying mostly Boeing heavy jets with an airline) without ever realising many things posted here.
Indeed, after finishing flying SE props, where, at least 40 years ago it was common to fly with pitch for speed I had to get used to the other system when converting to jets. For most pilots, as it did for me, it takes a few hours to get used to.
My explanation for the way to fly a heavy jet in the approach is: about the last thing You want to F&*$ U# is Your descent angle/glide slope. Even to the cost of overspeed if it happens.
For example at 200' You run into a positive windshear which tries to flatten out the descent and increase the IAS. Now I can cope with overspeed, but at that height correcting a completely destabilised approach angle is just alarming in a heavy jet. So what You do is to pitch down first and fight to stick to the G/S. Of course the second reaction is reduce some power, but that is limited, because who wants to idle a heavy jet at 200'?
When passing the threshold You decide if the overspeed is acceptable to continue landing or press the GA button.
One thing was stated in earlier posts was that You could never push during a flare. Anyway the B747 could easily cope with short pulsed pushed elevator inputs if needed to stop a prolonged flare. Slightly increasing the descent but the movement raised the main gears a bit and the overall effect was a smooth landing.
I still fly SE nowadays and would never allow a student to do that on a C172 however....