I think that compensating for the hit to both wheels on a smaller ramp and correcting position in the air on a bigger take off are where people struggle, me included.
The Pinkbike Ben Cathrow series "How to Bike" is a good one. Although the first episode is pretty poor, you can skip that one. They still haven't covered jumping yet but I think it will be coming soon.
I'm not saying coaching doesn't work, just trying to press how difficult it can be. At the beginning of the thread some of us were trying to put into words, how to start somebody jumping. The film was proof that this isn't an easy task even for a good coach like Niel Donahue. That even the best...
I think a bump jump over a piece of wood ( 2x4 ) is a good start. Bumping mildly with both wheel consecutively and like you say weightless. This gets the timing right and lift requires more input from the rider. More importantly the rider gets to acknowledge the hit to both wheels and...
I just watched your film. It looks to me like you are compressing too early and the soaking up the jump. I'm guessing that if you compress later and decompress on the ramp, pointing the front wheel a little more upwards, that you'll get much more lift. I know it's all easy to say... Does that...