I note that also - that some keep the legs moving at lights... That would be a 'philosophical' point in that episode of 'doing'. I try not to interpret the reasons or the purpose of it.

And as an ancillary to the 'never stop pedaling' there is 'rest whenever the opportunity arises and don;t burn matches unnecessarily'... this being a foundation of mass start racing (maybe group riding ?) . Whereas a one rider effort, like a TT, works under different. directives....

Just before reading the above quoted opines, I was thinking about my current riding... so different from my early days racing, when most (not all) riding was ina group or response to a group dynamic. It's where my stoic nature found further foundation...
back to 'warmup' - warmup, for me, is a total bodywide awakening, an awareness of every element to be needed and used - the equipment, of which the body/mind is an essential part- it's the prelude to whatever I'm doing.
and example of lack of same: how often are you on a group ride when at the END of a somewhat extended rest stop and the intended restart is imminent, someone announces they need to go to the john... LOL!
Ride On
Yuri