If Shearwater made this a firmware upgrade option, the tech and CC people can simply not buy it the same way they probably didn't buy the recreational Nitrox upgrade. HOLY CRAP!!!
I love dive snobs...
Not being a snob,... but just clarifying something here. The recreational Nitrox upgrade IS NOT an option that the owners of such computers "buy". It was a free upgrade for older models & is incorporated into units currently sold. Unless I am mistaken, the only upgrade (unlock), that I am aware of, available for purchase on the units, is the VPM algorithm. Shearwater has been wonderful keeping most of the the upgrades accessible to those who own their products, free of charge.