Currently, in 7. 1 at this time, you can terraform planets to be 0. 1 ATM of Oxygen and have 0. 3 ATM total and have just over -10 C average temperature and it will be just as a paradise as Earth. I suggest that its on the extreme edge of non-infrastructure survivability that it affect the population growth rate, agriculture and other stuff. Just because we can live on Mount Everest or the Death Valley doesn't mean people want to live there like Tahiti. So if its on the extreme edge of 0. 0 colony cost, it should have a penalty to everything unless infrastructures are still used. Once the sweet spot is reached, say within 25 percent of midpoint deviation (0. 1 to 0. 3 percent of Oxygen where 0. 2 is optimal). If temperature and breathable atmosphere pressure is at ideal, then there should be no penalty of any kind on agriculture, services, or population growth.
I can see the stats are there but I do not know if there any associated penalty for not being close to ideal.
