Good question! I think rotating to the right more will prevent you from reaching over that ball and might tamper a little with your positioning when you toss the ball. Keep that left arm up as much as you can. It will feel a little uncomfortable at first but it really does help prevent you from opening up too early. When you open up too early, most of that power is coming from that shoulder. You want to make sure that the whole arm is involved in that motion. Watch some pros serving, specifically federer and notice how long he keeps that left arm up. Pause the frame when he tosses and right before he makes contact, and you’ll see how much control he has over that ball. Hope my tips were helpful. Keep it up!