This is probably a naive question but are you talking about deriving the actual masses of the three generations of quarks from string topology? Something that would predict the oddly irregular steps from down to strange to bottom (roughly a ratio of - 1/16/42), or from up to charm to top (roughly 1/600/283).
I familiar with how CY spaces would have three "holes" for three generations. But is there even a broad brush understanding why the actual masses of particles should be so lacking in a regular progression?
Cheers - John McCrone.