Another "easy" thing to try Jack, that may or may not help, given A) I'm not a teacher/coach and B) the position of your arm (particularly your elbow) and chest in your trophy pose. But one thing I focus on might be of help to you, which is how you grip the racquet.
First, a little exercise to illustrate what I want to highlight. Stick your right hand out like you're trying to shake hands with somebody, making sure your pinky is pointing down towards the ground and your thumb is up with your fingers relatively spread and hand relaxed. Now take your hand without moving your forearm and tilt your wrist up and down, toward the floor and your pinky, then back towards the sky and your thumb. You should notice a decent amount of movement. I can move my wrist somewhere around 120 degrees this way.
Now, do the same thing but this time make a tight fist with your thumb wrapped along your knuckles (like you're going to throw a punch). You'll notice a lot more tightness across the top of your thumb and whatever the heck that part of your hand is called. When I do that I lose somewhere between 30 and 45 degrees of motion compared to an open hand.
I hold the racquet with a relatively open hand, and my pinky finger is almost off the bottom of the butt cap. I spread my hand out with the first finger knuckle of my index finger on the grip bevel that corresponds with the face of the racquet. The loose wrist and open hand gives my wrist some flexibility and the knuckle on that part of the racquet gives my grip the stability that would be lacking otherwise.
Check your grip, spread it out a little bit, and let your wrist relax. Make your fingers go "up" the grip a bit instead of straight across, and the same with your thumb. In addition to better racquet drop, you might also notice the racquet tip snapping through a little faster on contact, which also makes it easier to hit a higher kicking serve. You can really attack the ball. It works for me and is one of the few serve "checks" I regularly give myself.
Again, my caveats above...Not a teacher/coach, and these other guys have lots of good stuff to say about your arm/elbow/chest/trophy positions. The grip is just an easy fix that can pay off without changing your motion. Give it a try.