chuckebaby
tuning to different pitches is the oldest trick in the book to find a singers sweet spot.
if your not aware of this method, your missing something....a singer.
and possibly living under a rock where there's no articles on pitch manipulation.
so JB101, what you call a " tenth of a tone, or something "...(thanks for the laugh)....us musicians call a "half step".
or Eb tuning.
can be a significant change to increase a singers upper range.
but as far as this 432 thing... like I said in my previous post... "snake oil".
I have read many articles about tuning systems/ temperament (or pitch manipulation, as you wrongly call it), in fact a sizable part of my thesis was on this subject.
"We musicians" call tuning down a semitone (or half step) tuning to E flat (77.78Htz) on a guitar, so A= G# (415.3).
"We musicians" also understand that you have not changed the reference pitch, but when you play an "E
Shape" chord on your guitar in the first position, the resulting chord is actually E flat, and so on.
If you truly are an Assistant Engineer, as your profile claims, you need to ask someone at the studio you work for to explain about pitches. Perhaps they have a chart showing the notes and their relevant frequencies.
Until you understand these, then EQing, amongst other things, will be very hit and miss, not to mention the fact that you'll be out of tune with everybody else.