I was perusing Supplement 4: The Lost Rules. I happened across the following and realized that this is a pretty useful concept. I think it was left out of the game and I'm sure I've seen sectors that did not limit themselves by these defined values.
WORLD CREATION (Book 3)Atmosphere Effects (Alien Modules):Certain atmospheres on worlds dictate the minimum tech levels as shown below. If a world has the indicated atmosphere and its tech level does not meet the minimum, change its population, government, law level and tech level to 000-0 instead.

Atmo     Min TL
2-          7
3           6
4,7,9       5
8, A        8
C           9


I think C ought to be 10 TL+. I also think some of the taints might be handled by a modified human (a genetic change vs. mechanical coping), though that may apply to 3, 8, and if you want to start heading transhuman, A or higher.

Tom

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“The only stable state is the one in which all men are equal before the law.” ― Aristotle