I cant reply to this question, but I have my own regarding this matter:
Well, that is a something that bothers me since I discovered UTAU: Is Kasane Teto's voice edited or not at all? I remember some users claiming it was, however I never found any official statement about it? One of the VOCALOID wikia users said that she was edited by using VoxWave, however I am yet to find any connection between Teto and VoxWave at all
In my honest opinion, she is only voice acted, right?