Hi aschiller and Oli,
No, unfortunately running SBS as „pi“ is not a possibility.
For now please note that the pulse framework is only activated when you use our Bluetooth plugin. Otherwise, you should get all ALSA features including „arecord“ and should also be able to use it as your input for waveinput.
But, we will try to test this with the Digi I/O and let you know. 😉