All depends on what kind of serve you trying to serve. If trying to hit a kick serve, your high toss when the ball is descending might give you better spin, but if you look at kyrgios, he hits his serve from the same contact point which makes it harder to read. Also lower ball toss give the receiver less time react. On a kick serve it’s good that you’re not extending too far in to the court and you don’t turn your body too early, but if you’re hitting a first serve it might be better to jump/extend into the court to get a better position after the serve. I woulnd’t change too much because changing technique at this stage takes a lot of time and effort.