I think there may be a bit of confusion here. All the streamers with volume pots or software volume, only controls the analog out volume. I am not aware of any that that controls the digital out.
Streamer with variable digital output
In my setup, a Bluesound node feeds a Peachtree Gan1 digital amp/power dac. The Gan1 has no volume control and a digital input only. What other streamers have a variable digital output for compatibility with the Gan1?
BTW, I ask out of curiosity. The Node to Gan1 is a wonderful option for anyone looking for two small boxes and one interconnect for less than $2000.