Is this another rule another rule I can throw out and replace with a principle?

Uke presses firmly on Tori's knees

Uke is pressing firmly on Tori as in the still above. There are ways to perform the kokyuho I gleaned from studying Saito and Nishio senseis, but Endo does something simple that I never thought to do because I have been thinking about the rule: don’t move around. This must not be a rule.

Endo Sensei takes a step back

Cuts down, not raises up

... and done

Of course this is not basic waza, but why fuss over it?