BandHelper has long had multi-route audio output capabilities -- the ability to play Recording 1, Recording 2, Tempo, Starting Pitch and a spoken text field to the headphone jack or specific channels of a USB audio interface. However, this feature is not commonly used and seems to have spotty compatibility with audio interfaces. So here's a list of devices that myself or other users have found to succeed or fail with this feature.
SucceededRoland Duo-Capture mk2
Tascam US-16x08
iConnectAUDIO2+
Steinberg UR44
Focusrite Scarlett 4i4
Universal Audio Volt 4
FailedBehringer UMC1820
Soundcraft Ui24R
I'm happy to test further with any of the failed hardware if any US-based users want to mail me their hardware and I'll mail it back when I'm done.
