With a stereo device, I would find it helpful if the Test Tone could be applied to either channel for identification purposes.
Background - because of our environment, we sometimes move our analogue desk from the Control Room (where we use SCS during our plays), to the auditorium (for live gigs). On its return, it would give a warm feeling that we had reconnected our PC to the desk correctly. Really, I should probably just set up a test show with a hotkey per channel. That would work regardless of my mix of stereo and mono devices.