Hi John - thanks for your view on things.
I think the big question about this kind of practice is whether repeating it again and again will get you there. People like Dan and Mike talk all the time about the need for regular solo practice to develop these "lines" internally (and Kanetsuka Sensei among others keeps hinting at this too), but Ikeda Sensei didn't talk much about this aspect at all - not in the classes I was in, at least .
If you look at how Dan, Bill Gleason, Howard Popkin Ikeda Sensei etc teach, it seems to me the focus is on getting you to feel it first, then follow that up with a consistent solo practice that "burns in" the body habits. For myself anyway, it was the paired connection exercises in which every change I made with my mind / body instantly reflected back to me what I was or was not doing that really made me understand what I was trying to do. Now that I know more about what it's supposed to feel like and what it even means to have different parts of the tissue structure really connect, I can do solo work and have it make sense to me. I really think that this is what Ikeda Sensei's trying to do, get you to feel it in the first place.
As for the folks that think they're doing this already... well, it's up to the uke to give the proper feedback that shows where this is true or not. Ikeda Sensei's ukes are not "tanking" for him. The Uke role in this type of learning is very important. The uke needs to give good connection. If you run into their structure, they shouldn't move, if they get it right you don't "mess with them" you let them feel the result of what they are doing. As they get better, you can provide them with a connection that has more structure so they have to get better. But it isn't your intention to screw them up and it isn't worth anything if you are "tanking". That's why its best to get time with the folks who are well ahead of you in this process. They can tell what you are doing, give you just enough juice that you have to put another piece together but not so much that you are just getting shut down (unless you are really screwing up). The ukes job is to facilitate your learning. When two partners train together and both are clueless, the process gets pretty screwed up.