@ThimothyH - very kind. Thank you.

On the topic/off topic of pedaling I am talking to a new/potential coach. He was discussing with me his seminar he is giving on pedaling technique and how to bring other/different muscles into the stroke. The idea is as you bring these new muscles in you rest the others. No comment on there particular style, but where we totally agree is the human is much different than a mechanical machine in that the fatigue part comes into play. What is most mechanically efficient may not be maintainable.
You see these guys doing 170+ RPM on rollers. I used to free spin (no chain on cranks) on a trainer and at those super high RPM, I was exhausted, while from a physics standpoint I was doing no work other than spinning a circle. So while mechanically 50# pedal force @ 70 RPM is the same as 25# force at 140 RPM the rider energy/effort is not the same. And the fatigue in the legs is not the same.

So to rollers and pedaling and style - my opinion, not science, but I road them first about 1976.
Every rider needs several pedaling styles and they need these to be reflex and selected naturally. A smooth circular pedaling stroke (where force is applied as close to equal over the as much arc as possible) is best where force is low (generally higher cadence). Force has to be lower because the muscles that are taking the stroke back and up are nothing compared to the ones that take the pedals over the top and down. Spinning is more aerobic and will minimize fatigue in the muscle and clear them from waste build-up from the activity itself and the prior days of training. Using rollers to spin out the legs in therapeutic. It is also great for warming up, however many prefer a trainer for that and don't want to worry about concentrating.

When it comes to high power, most that power is going to come from the two major muscle groups the quads and glutes and the other muscles can't play in that range. It is not reasonable to try to develop hamstrings to pull back with the force you can push down with. So for the same power, the rider has to back off pedal force and spin more, or really bring in the "big guns", more force, where down stroke from glutes and quads will result is a bigger difference in pedal force through the arc. That will result in more of a stomp type stroke. The result will be more power and maybe more fatigue (more muscle power = more waste). There is a ratio of pulse to rest that works for every muscle. I tend to think that is personal.

Example math to explain what I mean is using 120 RPM = .5 sec a pedal rotation (for easy math) which is better:
.1sec power contraction of 50lbs for 20% (1/5th) the 360 degree arc = 72degrees of arc (2 o'clock to 4'oclock)
muscle relaxing .4sec each rotation.
OR
.05sec power contraction of 100lbs over 36degrees of arc?

The numbers were for illustration and reality is not 2:1 ratios I used for the math. It is similar to asking if it is easier to lift 100lbs 10 times, or 50lbs 20 times in the same amount of time. It of course depends on the muscles/lift, the person and the training.

Anyway due to different muscle ability, position on the bike, fatigue and waste removal, and having seen some private data,...and personal (kid) testing, spinning on rollers was not the ideal stroke for getting the most power on a road bike.

To the degree roller spin training teach a rider to spin when they should "stomp" when needed, it is not a good thing to do. If however rollers are used to chill, get comfortable, do more aerobic lower power work, they are great.