I think you mean if you want to use the coaxial output. uDSD only has USB input.
So by using the coaxial output you are essentially using uDSD as a USB to S/PDIF converter, probably to feed your high-end DAC that has no USB input.
Yes, this is what I was wondering, just didn't know if it could be powered from an external PS rather than the USB input.
Sounds like a good solution as a converter and at very low cost.