We need the, HOW!
Pull what? Pull with what? Pull when?
Push what? Push with what? Push when?
This idea that the grip, wrists, and arms are very relaxed, sometimes described as “spaghetti like” I think is not only NOT helpful but can actually be harmful.
This concept can lead to a total misconception of how it all works, especially for the serve.
As I like to say though, “try it”. Do your dispersion study and see what works, then see if it is effective.