Sometimes I need to sit and listen to you for a while, Dana, before I find out we are in agreement. We just have different languages.
My dog does the same kind of stretch thing that your cat does. I've had cats before I got the cat allergies, so I understand what you're talking about. As you know, he's a Ridgeback and still very young. Right now he's too wild to be let run around the house. So he mostly stays in his pen, and then gets lots of long walks and some play with me.
When I first let him out of the pen, he doesn't want to go on the leash and go out - yet. First there is the ritual flying kisses from the excitement of getting out. Never seen another breed do that... Then he goes through that dynamic tension and range of motion stuff. I have to wait for him to finish before he'll cooperate and sit long enough for me to get the leash on. Then he's good to go.
And boy can he go!
Resistance training is resistance training. Uechika have a different spin on it because they need to have brutally strong tiger hands while doing basic things like stepping, sliding, shifting, and turning. Truth be told, I think they developed this kind of training because the rice jars were there. Had they seen folks doing classic Olympic lifts like power cleans or clean-and-jerk exercises, they might have instead latched on to those (pun intended). The jars however do have that wonderful ability to get your hand in that powerful, functional boshiken shape. There isn't anything quite like it.
Anyhow, carry on, Dana!