@Nige_S, as I wrote earlier, I don't know a way to post images of movies to the KM Forum to illustrate, but what I'm doing moving the destination Mac Mail folder OUT of the subfolders is basically simplifying the path, thinking that would make a difference with the failure of my "Move Message to…" KM Macro. It does not.
Also, this nesting is no more complicated than it has been for a long time, but this KM Macro behavior is a new one.
Perhaps I should do a complete remove and reinstall. Is there a KM Forum area that addresses this? I could not find anything excepting this: