Wow! Your backhand is fantastic! Your footwork is excellent - solid dynamic balance, great power wave generation. You are getting a good snap in the load phase so you should be generating plenty of control and spin, and you always seem to find the sweet spot of the racket face. So, stroke good! I am presuming you are holding the racket with nice soft hands (no death grips allowed!)
As for tweaks you could play with:
- for a little more power you could experiment with delaying the moment of contact few milliseconds longer to take the ball a little less in front
- again for power experiment with a more open stance especially when hitting crosscourt
- for control and spin a tiny bit more counterrotation just before the load (drive) phase to set your forearm muscles (back then forth)
If none of these helps MARKEDLY then don't change a thing. There is nothing fundamentally wrong with the physics of your stroke - Nadal would be proud!
