I'm all for the light. It actually does make it easier to identify MOST teams.
However, our team had bright red frame and 639 was in huge letters on sides and back upon a white background which was really easy to see.
The rule I don't like is how the judges want numbers on 4 sides, as in the four sides AROUND the robot.
For stackers, the actualy front side is not a very good place for the number. Reading the rules carefully, the number can be placed on any 4 sides at 90 degree intervals. The top is then a much better side for stackers yet most inspectors didn't seem to think so except one who went and READ THE RULES.

I think 3 sides is plenty for identifying a robot, along with a light. It's not like the robtots are covered in styrofoam peanuts.