I get where you’re coming from. Even though I might not be able to go super fast, the ball seems to be heading in the right direction. My smashes are pretty accurate, and if you do the math, you can figure out the angle the ball’s going to take. I think this is still a great way to get a feel for the kick motion, especially since i can see if my wrist is loose, so I can just use the motion to brush the ball without trying to force it. About the throwing exercises, I agree that it’s amazing how much tapia can drop the racket and how his shoulder, arm, and wrist move when he charges at the ball.
I'm sure you can brush the ball better than Rapunzel brushed her hair, I'm just skeptical it will translate at all on-court. I say this as someone who wasted a lot of hours on smash-related exercises that went nowhere. If you're not practicing at full speed, it's a beginner exercise, and you're no beginner. You need intensity to see improvements in your structure and coordination.
Cheeky edit: In another comment you mentioned you lack explosiveness, which really adds to the point I'm trying to make. You need to find ways to practice at 100% intensity or above, not gentle pattings of the ball. Something like this if you can't get on court: [https://www.youtube.com/watch?v=9w3xwYIx17s](https://www.youtube.com/watch?v=9w3xwYIx17s)