Is that a GPIO breakout on the lower (larger) board? If so, maybe it could be something plugged into that with the LED(s) near the surface of the Checkmark vent. I know you said it had been thought about, but could it be thought about again? As an optional extra or user fitted option? A kit? A DIY doodad? It would only need to be a connector, resistor and LED at most.
Or are there other things being considered for that port?
