Great Article! Reading it reminded me (at least to the best of my knowledge at this point in time!) that THERE ARE NO OPEN HARDWARE CD/DVD PLAYERS . I think some person or people should attempt a completely open hardware CD and/or DVD and/or Blu-Ray player... I'd be happy with just a completely open hardware CD player...
IMHO open software/firmware would already be far more useful, because then you could read discs at a far lower level which greatly aids in data recovery situations; something like the optical disc version of a https://en.wikipedia.org/wiki/KryoFlux , in other words.
The hardware in a drive is very high precision but otherwise quite "mundane", as the article shows.