Wow, I don't know where to begin with this one. Either the engineers have completely lost all knowledge about how their controllers operate, or nobody has the right mind to think about putting opaque labels on the EPROM chips or over the controller board itself?
This kind of stuff borders on urban legend / cargo cult engineering territory.
Belt and suspenders.
And the conclusion?
"They also confirmed that the light from the Canon flash and the Polaroid flashbulb could be effectively blocked by "black bagging" the flash, or by blocking the EPROM window with "tin foil" held in place by clear cellulose tape, or by blocking the EPROM window with "standard electrical tape."