It might be invalid to project the performance of a 40 amp PD converter onto the 60 amp version. Looking at the pictures, there are two different physical designs, one for the < 60 amp models, and another for the >= 60 amp models. At one point in the past I saw specs for the converters that included the switching rates, and they were different for < 60 vs. >= 60. This is pretty good circumstantial that PD has two different converter designs, and it might be careless to assume they behave the same at the edge of their specs.