Not sure if this fits here but this 1971 article by Kuroiwa Sensei has some interesting comments/principles which might relate to recent discussions on passing on knowledge of "aiki" etc. The 5th para on is particularly relevant.
He may not be talking about the same "aiki" as Dan and Mike etc but then- maybe he is
http://www.aikidojournal.com/article?articleID=558
Ellis Amdur offers a very gracious snapshot of Kuroiwa Sensei here:
https://www.aikidojournal.com/?id=138