According to the designer the USB input on the Holo May is the preferred one so try it until the DAC is broken in. I have both a May KTE and a Spring 3 KTE and I concur with the designer and see no need personally for a DDC. Your money though if you have an itch. I would and was more interested in finding the right USB cable.
What Digital to Digital Converter Do You Use? Why?
I have an iFi Zen Stream and am considering using a digital to digital converter to convert the iFi's USB to i2s into the May Holo DAC.
I guess the question that arises is if this approach is sonically better than USB directly into the DAC.
So, who can offer some advice based on personal experience? Yes, I do realize that your DAC and streamer differ from mine.