I agree completely that it would be valuable to have a signal confirmation in the uTrack app. If you are doing some complicated routing, it’s possible to forget to change the card output. This is a really good feature request, and would put the uTrack more in-line with what we expect to see from the likes of JoeCo, Sound Devices, etc.
However, aside from simply forgetting to do it, If you have a thorough understanding of routing in the S32 or M32, it is quite simple to be confidant beyond any doubt that you do have a signal. Output to the uTrack will be the same as to a DAW, direct from the pre-amp or source, so it will be completely unaffected by anything you do while mixing a show, other than gain adjustment.
The easiest way to assure beyond a shadow of a doubt that you are recording what you think you are recording, is to make sure that your outputs on the Routing > Card Out match your inputs under the Routing > Home tab. If these are the same, what you see is what you get. If you change routing frequently, you can set a scene to apply these settings.
If you follow these steps, there should be no question as to weather of not you are recording the same audio tracks that you see displayed on the audio meters on your board. This is why having audio meters on the tTrack app is irrelevant. Nonetheless signal indicators per-track, or at least per-8 channel bank would be a valuable feature. I think it’s far from a make or break for the great value of this device, but I definitely second your feature request.