Takuma Hisa is exactly the person I was thinking of. He learned Daito Ryu from Morihei Ueshiba first, then Sokaku Takeda. He didn't seem to find anything wrong with Osensei's pedagogy. He even ended up calling what he was teaching "aikido" and insisted it was the same thing.
If things did change, what were they? The fusion with Omoto-beliefs perhaps or is it just a case that he wasn't teaching much later on. I recall an interview with Takuma Hisa in which he had something to say about Takeda Sensei's own enlightenment, not totally dissimilar to Osensei's.
It seems the teaching methodology indeed did change after te war, according to Doshu Kisshomaru.
"You mentioned earlier that O-Sensei in his later years would demonstrate his technique in front of his students and that the students learned Aikido by watching and being attracted to his movements rather than O-Sensei teaching them. Was O-Sensei's teaching method like that from the beginning?
No. At first he taught techniques point by point although it didn't seem that he was attached to a specific teaching goal. But he emphasized that you have to do things exactly, one by one, so you won't make mistakes. Recently, there has been a tendency for Aikido training to become too soft and flowing and some beginners lightly bypass hard training. That's not the way it should be. If you are going to practice you must practice basics earnestly. This he told me frequently even in his later years… exactly, not changing anything… if you don't reach the level of softness beyond technique by getting the basics down perfectly, you won't develop true strength. If, from the beginning, you practice a "tofu-like(bean-curd) soft style, you will be vulnerable to an attack. So it's necessary to do solid training in the beginning. Over time, through this kind of solid training your technique will become effective. A soft effectiveness will emerge"