well the Pythagorean comma and how to divide it amongst the octave was the central objective during the whole evolution of temperament (from meantone to modern day 12-tet).
So that takes us back to at least the 15th/16th century
That is more theory than practice unless you want to reduce Pythagoras down to a comma. I was referring more to people who decided to take Pythagoras and related writings as gospel.
