Feature request: volume control on USB DAC on Lollipop

[glider]

Android 5.0 supports external USB DACs. I'm using my HRT Microstreamer successfully with DSub on a 2014 Moto X and Nexus 5. Volume control isn't using the volume built into the DAC, though, but digitally controlling it within the phone. The noise floor is pretty high on the DAC which results in a lot of hiss with my Shure IEMs. To solve that I'm running the volume at full tilt and using a downstream hardware volume control.

That's a lot of wiring, though, and the Microstreamer apparently has an analogue volume control built in (I think some other headphone DACs do too, with a standard mechanism for addressing it over USB). Be really nice to be able to use that and skip the extra wire and lump.