Miyagi said : Think, you will figure it out yourselve.
(Tomohuru Kisaki, Takeshi Uchiage through his father Kenzo, Eiichi Miyazato in his book).
It is good that kata are investigated by various methods to come to a better understanding. But although Miyagi was not omniscient, he did create the Tensho kata, so I guess he pretty much knew what he intended it to be.
The comment about the push-hand drill was not intended to be about how you train but more towards what to conclude. For me the two-handed drill is not the ultimate conclusion on tensho (looking at the title of this thread). That is what I meant.
Splitting up the kata regarding views on soft and hard. The name Goju-ryu came around 1933. Miyagi was teaching the kata already from 1917. The principles of hard and soft are found in all karate, not just goju-ryu. I agree that the cluster H kata start from a hard perspective and that kata like seiunchin/tensho more encompass soft techniques. Miyagi certainly added tensho to underline the soft aspects of what he thaught.
But I feel that hard/external systems from shaolin derived styles have their starting point there and will evolve eventually to softer and with more emhasis on internal aspects. It's just a starting point to begin with. Eventually using hard/soft internal/external becomes one in body/mind/spirit.