Optimal Launch angle is found in your timing. Imo.
SAY IT LOUDER FFS! LET THE LAUNCH ANGLE PEOPLE HEAR YOU! LOL. Stay short in the horizontal and the vertical. The way my brain processes it.
Can't stress this enough ... someone instructing the concept of swinging down should not have the barrel heading down at contact.
Keeping the hands high? Or just higher than the highest strike? Higher than that doesn't equal better. Directing the knob with intent of down to is what should be the goal . Let's not complicate this simple easy cue .
An instructor shouldn't instruct with the barrel in mind , especially for beginners. The knob should be the focus