Thank you. I suspected it was out of place. The idea of doing the pop-ups, as well as power skipping for height (both drills resisted w/ weight vest & unresisted) in the peaking phase came from a former coach of mine who had used them with the high school state record holder in the days leading up to his 24'9 1/4" jump at the state meet. He said he absolutely exploded off of the board, and that it would have been closer to 26' if the pit didn't come to an end (he had to go in standing up, or eat fence on the other side). I suppose I was swept away in the allure of the tale.
Anyway, I think #3 on your list is my jumper's problem, and I will get some video and have a look.
It may, possibly serve a purpose as a plyometric activity.
You mean in an earlier phase of training, such as SPP, correct?
Anyhow, I'll have to have a keener eye for what's going on biomechanically in those last 3. After all, misguided power solves nothing! Boom!