Certainly created the categories to tags, but it deleted 12 of 22 categories. Didn't back up before I activated, so my bad.
But . . . . . grrrrr. Have to go back and recreate the whole menu - another 2 hours wasted.
[edit add - just reactivated and read the instructions - duh - you clearly state it creates orphans. the problem now seems that it is somehow effecting slugs]