Typically what you would look for would be high frequency roll-off characteristics due to the capacitance of the headphone itself. The 135pF of the DCA is not particularly problematic with the Stat, so there are no concerns there.
If you knew the drive voltage requirement for the DCAs, then we could do some analysis on the output stage of the Stat and its capability in terms of slewing at 20kHz at those playback levels, but that information is absent from the product information that I can see.