I don’t understand why people who can’t hear have so much to say on these audio forums.
Years ago I had a buddy, a musician with perfect pitch. He came over and tuned my piano with a single tuning fork. Even then he didn’t really need the tuning fork. It was for my benefit to show that A was the right pitch. No chromatic tuner, no measuring equipment needed. Best the piano ever sounded.
If someone needs measurements to confirm for themselves what they are hearing, that’s fine; but why claim others are deluding themselves for not relying on measurements?