I've found from my own personal training, that while you "close" the waki you still keep it "open". There's always a "contradictory" nature of power going on in each joint. Absorption of energy also happens not because you want to absorb it so much, but as a side effect of maintaining this contradictory power (closed but open, open but closed, extended but contracted, contracted but extended) in each joint.
When you drop the shoulders, it might be interesting to play with the feeling of droping the shoulders "into" the elbows.
There's still a sliiiight feeling of tension in them as you try and maintain this feeling
It's the difference between being relaxed & just "slack"