This applies to all exercises, not just this one simple example, the squat jump.
You can squat jump to complete the rep, and get the set, and workout overwith.
Or you can squat jump with your spine aligned, get down as low as possible, and explode up as high as you possibly can, attempting with all of your might to have your head go through the ceiling, on every rep.
There are two ways to train.
Only one of them is serious and gets results.
The other one, I have no idea where that gets you, but it’s probably not very far from where you are right now.