I can understand your frustration but I think the main purpose for Variaudio is working on mono vocal tracks.
I am using it to some extent although I’m not satisfied with the quality of the shifted notes.
As long as I am using it to do minor intonation or timing corrections, it is ok, When I try to derive backing vocals, the result gets worse the more semitones I go away from the original.
From my point of view improving the shift algorithm is much more important than expanding the frequency range. But I would also support your claim… I can understand what you need it for.
I hope that we will get that improvement with C6, otherwise I would have to purchase Melodyne which does a great job on all these issues.