"Powered" means not to small of a kite. If you pull the bar it nothing happens you don't have power at all.
If you pull the bar and the kites want to pull you away, then we are talking power!
And yes, you increase the power with board speed. But don't expect a big jump if you are riding fast and have a too small kite. Speed will help to get higher, but for more height you need power in the kite, speed and good good lift off (powerful pop and a little kicker or perfect flat water).
84 kgs...well, try a 14 one day and you will see what I mean with power. But only if you feel comfortable and safe in handling it.
A safe spot is important with space for safe launching and landing.
My kites are set to be slow...therefore inner bar settings on 32m lines. But this has nothing to do with jumping height, but rather for being able to land my tricks.