You're looking up the wrong tree for false beat sources. Primary source is bridge pins being ever so slightly loose and notching being poorly done. The strings need to fit around the termination points snugly to prevent falseness, some falseness can be caused by feed back from the board and sympathetic vibrations from secondary scales (duplex aliquots). Modern string is very well made so irregulaRITIES in diameter and shape are inconsequential for us, over pulling strings is not a problem unless talking about four or five semitones or more and twisting strings has had no observable effect on tone. Not to say tonal variations don't occur but normal twisting while stringing is not an issue. If you have a RCT you can experiment by taking measurements, take a string off the pin and give it a 360 turn and put it back on the pin and remeasure and compare. I would try A4 AND a5. oNCE A PIANO IS UP TO PITCH ALL THE STRINGS ARE LIFTED TO GET THE CATINARY CURVE OUT OF THE STRING AS IT APPROACHES THE AGRAFFES IN ORDER TO GET DEFINITIVE TERMINATION. iF THIS IS not DONE YOU WILL HAVE FALSE BEATS EVERYWHERE, FOR SURE FOR SURE. wE HAVE LEARNED A LOT ABOUT MANY THINGS SINCE w. b. wHITE WROTE HIS BOOKS. mUCH OF WHAT HE WROTE IS STILL USEFUL TODAY BUT SOME OF IT HAS BEEN SUPERSEDED BY NEW INFORMATION. nEWTON
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