It mainly just suggests that optimizing for DTR is based around optimizing around these damage breakpoints, which nobody really knows where they come and how exactly they are implemented. But that the higher potency your abilities are, the easier it is to hit them, due to the nature of [potentially] truncated damage.

I'm mainly pulling on the work of people who are much better at this sort of thing than I am, and am assuming that the work of Eein (chocobro.com) and the like is fairly accurate. It all points to the weighting for DTR being majorly inferior for SMN vs. the work of someone like Valk, who draws a contrary conclusion, where the major distinction between the two classes is potency.