I think we've about "saucered and blowed"* this one by now, but I am
curious about how those series strings handle the reverse voltage across
the LEDs. Do they have diodes or resistors across each one or do they
just depend upon the summed inverse breakdown voltages keeping the
reverse current from ever getting large enough to blow an LED? I'm
guessing maybe that's it, do ya happen to know the answer?



They depend on the latter, don't think for an instant that these things
are over-engineered, or even well engineered.

Really though, in practice I've found LED's to be far more tolerant of
reverse voltage than the specs would indicate.