I used the analog version of this mic long ago, and have purchase requisitions on my boss’s desk to get a couple of the D11s as we speak. So my recollection is a little foggy. But…
If you set the transmitter to “LINE” you’re just telling it the level of the incoming signal. It will then normalize that signal and send it to the receiver. The receiver will not know whether or not the incoming signal originated as MIC level (the included capsule) or LINE level (an external source such as your console). The transmitter is then going to provide a mic-level signal to the camera.
What I don’t remember is if there’s a setting on the receiver to specify line level. If there is, I believe it’s in the menu, not just a switch. This is where my fuzzy memory is a problem.
Evidence of this is that you get clean sound as your original post described. I wouldn’t worry about it.
Cf