Since we already are doing that we can relate to how what Endo, Sensei is doing feels like. don't Testing is progressive. By testing I mean giving appropriate resistance according to the nage's experience.
Well that is that....... Nothing much I can add to your experiences or training processes.
My experiences, and mine alone, tell me that one goes in and out of phase any number of times during any single run through with any one partner........most are just not aware of it though the set of circumstances that guides the training model. When you go out side your local arrangement, when you go outside your association it becomes more evIdent. This is only a concern if one is still looking for something other or to add to what they are currently doing......if not be happy.
I can't comment on what you are doing or what you are not doing.....we have never crossed hands. As for Endo Sensei...I can see what he is doing, can see hints of where it is coming from, but if I want to know for sure I have to feel it. I don't have to totally resist...just make the connect and see what I get back. Of course that is what my experience tells me.....