henka = variation
From the perspective of koryu where orthodox kata and henka waza are clearly defined, I cannot imagine the term henka waza being applicable to aikido. Why? Because there is no agreed upon "orthodox" version of any technique in the greater aikido community. Given that Ueshiba was altering/modifying the execution of his waza throughout his life, how would you determine what constituted a henka? Henka would be a variation compared to what or who's orthodoxy?
Many high ranking aikido instructors have discussed this topic with me thru the years. Greater aikido technique is so diverse that there is no possible criteria available to determine what constitutes henkawaza.
Toby Threadgill / TSYR