Well tenshinage is a technique. I used to be taught different explanations as to what to do depending on how good I got at it. Basically from leading ki down and up, in two directions, form centre. Then onto taking into account centre line. Then how it's taking the mind up and down ie: splitting the mind etc. Eventually it became opening up. Opening up the opponent through being willing to open up yourself. This led to more reality on operating from hara.
From hara you feel the yin and yang, the taking in infinitely and the expansion out.
Now sitting comfortanly and letting the body move with it your arms and hands may go out sideways as if welcoming the universe. However I find when I am focused foreward yet returning to hara the the arms do as you describe. The feeling is very similar if not the same as tenshinage. Thus I could say tenshinage is returning to basic posture or say it in some profound way.
That's my take on it.
Now if you want to see me doing it, which I find myself doing to different degrees and only more pronounced depending on the circumstances you can watch a video of mine. Not saying anything to do with anything else just that I tend to do it or similar to it naturally at times. (video: spirit of loving protection 2, from 2:35 onwards)
Again you use your own video as evidence to support your theories.
I have never seen you move in accordance with the the things you say you can do, nor have you demonstrated anything on film that is cogent with your writing. No one who is actually
expressing in/yo would move the way you do. In fact their structure would not allow them to move the way you move. It is almost impossible to understand what In/Yo is, and moving from center
as you yourself claim to know and do...and then move the way you do. I would have to completely take my structure apart in order to move and respond like you.
I never expected you to wade in with yet another reference of how you
move like Ueshiba!!
Comparing yourself to Ueshiba, particularly in regards to this aspect of his training and what it really means is strikingly divergent from any real understanding of what Ueshiba is doing and demonstrating.