i COULD post pretty extensively about this but the 432 v 440 craze isnt something that anyone can place any verifiable truth on unless they go back through time and try all tunings for A. Ultimately the tuning remains the most accessible, and accessibility is probably evil, But until bach and mozart they didnt have cross scale tunings that made any sense until the pioneer geniuses came in and stabilized them. Intervals had varying degrees in the microtonal spectrum until it was generalized and early players of greensleeves found them selves retuning piece by piece on lutes. etc. . Its only because extensive study has been done on this that we can even approximate the gregorian chants from the middle ages. My final say is God, when armageddon pits the hateful against the loving you will know the real tuning, until then what do you have? some sideways theory that means nothing