Airport Express feature request: audio via usb-out

A friend of mine, suggested me to put a DragonFly DAC between my Airport Express 'receiver' and amplifier (connected via cable) to boost digital audio quality.

The DragonFly DAC is a relatively cheap but high quality DAC with the form and size of a usb-stick, that gets it's digital audio in via usb, and delivers it analogously to a mini-jack out.

Since I understood that the Airport Express does not delivers audio via its usb-out, I am curious if that would be technically feasible at all, and if Apple has plans to built in that feature in a next gen Airport Express.

Is there an Apple employee in this forum who can tell me more about this?

Please let me know.

kindest regards,

Igor