Yeah, I'm really happy to see you offering this, but I can't help but thinking... don't you have an airplane to fix??
but to echo Charlie, the PWM output for in-tank fuel pumps would be a nice option. And an OBD2 or CAN output.
It would certainly be nice to see the EM3 combined with this, simply because of the recent advances in cheap, large OLED screens would allow for a very nice and easily sunlight readable display screen, but I suspect it would be best and safest to keep these as separate instruments. As I've discovered, the accidental grounding of any 5v sensor line has undesirable effects on my engine monitor, so I'm happy to have the EM & EC separate and just communicating data.
Todd