Exercise Scheme, Partial ROM Questions

I recently came across a video of some of the Chinese weightlifters training on youtube and one of the exercises I saw them doing was something like a partial range of motion front squat (used for bringing up the jerk no doubt.) Has anyone been using this exercise and with what rep scheme.

Also I’ve read in different books most recently Greg Everrett’s weightlifting book about a 1 and 1/4th squat, but I’ve never seen it in practice or in any of his or Mike Burgener’s programming. Any Ideas?