Re: H. Saito does 31 count kata.
I have been taught that Aikido is not a "kata system." It is a concept that informs all of our martial movements and even our interactions in life. As such, we use aiki weapons kata as a tool to develop and explore important facets of movement, balance, ki contact etc. We honor our teachers by learning the great forms such as Saito Shihan's published 31, 13, etc. but I have never read any statements from the Aikido greats suggesting that these movements are sacred or sacrosanct. Whenever I encounter variations in famous katas I ask three simple questions. "Is it performed well?" "Does it explore a worthwhile movement or concept?" "Is the movement martially sound?"