just wanted to update my view on this. some additional research and asking around, I'm now convinced that I was wrong about the Matsubayashi 'lean', and even wrong to refer to it as a lean.
The kata Fukyugata-San in my video is a good example of someone doing it wrong.
It's not even referred to as a 'lean' but more of a sinking slightly forward just as most of you were saying. I'll work on those two things: forward sinking and whole body power generation. ...keeping in mind what the hips are doing.
...thanks everyone for your input as I try to figure out how this system works. -Ed