[Matt C]

I wasn't necessarily thinking of "spying" on the opposing alliance, just a set of eyes able to see why the robot is stuck, or if it has cleared a field element while not in complete view of the drivers due to robots/balls being in the way.

You do raise an interesting point.
If you can use white boards, you need to find someone with good handwriting to be your robocoach, and someone able to read that writing from 45 feet away to be on your drive team.