I also feel I understand Ueshibas way of learning which to me was the way of learning and indeed teaching in those circles, a way I have seen westerners belittle or not understand.
Their way was to teach basic principles and leave the student to keep practicing, practicing, practicing until they understood. Thus the same view should be applied to how they learned. Ueshiba would therefore only be interested in certain principles he saw in a type of swordwork or jo or spear or whatever. So he wouldn't need too long to get what he wanted in order to go and then practice practice practice.
I think I agree with you that Ueshiba taught principals and left it to the student to practice until they understood.
However this is actually very different than the way koryu are taught. Classically, the Sensei teaches you kata
and that's what you practice for years. You learn the principals intuitively by practicing the forms under the guidance of a master teacher. I have heard that principals are elucidated at certain intervals by revealing gokui to the student, but only after a long period of grinding.
I am very comfortable with the idea that Ueshiba taught principles and not kata, and I am also comfortable saying that I am not convinced this is the best way to really transmit the art.
....and with that, we're off topic.