There is a difference between landing with a slightly bent front knee with flex and still being firm. The way he finishes with the bent front knee is called ‘chasing his front side’. Think about it like driving in a car without a seatbelt…if you hit a wall going 80 mph you would fly through the windshield…well the wall in your delivery is the firm front side…the energy throughout my delivery that has been built up is what flies through. You should not think about getting ‘extension’…its a myth and damages the body…extension is another term for pushing the ball. You release the ball at the highest point…its physics…you cannot throw the ball out front nor would you want to. Its a full pull against a firm front side.
Think about staying tall in the backside…not straight up and rigid but taller in the back knee.
Marry the head to the inside of the landing foot and that will clean up directional issues created by rushing off the rubber.