did a crude test in serum lol
sub osc plays fundamental, osc a plays 2nd and 3rd harmonic 30 cents up, osc b plays 4th and 5th harmonic 60 cents up.
note# (just keytracking) is mapped to global fine tune so the harmonics line up a little bit better when playing octaves
basically i would like to experiment with emulating the inharmonicity of strings, like in a piano