Partial pressure is what it is - it's a real, physical measurement, not a game rule - so you can't "mute it"
. Your example world would have an O2 partial pressure of 1.5*0.2 = 0.3.
Oh, I understand that. I was trying to come up with an approach that would create a sort of bell curve for oxygen content, so that increased ocean coverage and increased atm density offered a diminishing return.
And now I'm thinking that the weird mistake in 2300 is associating ocean coverage with a percentage
of oxygen, when it ought to be a volume
of oxygen. Regardless of how much other gas is there to start with, a plant's gonna produce what a plant's gonna produce, right?
There should be a chart that multiplies ocean coverage by planet surface area to determine a quantity of oxygen, which you'd calculate as a percentage of the total atmosphere.
A world that's Earth sized, with 70% ocean coverage, produces the baseline, 0.2 bars or whatever is an easy number. Earth's atm is 1 bar, so ppO is 20%
A world that's 5,000 km in radius, with the same ocean coverage, produces 60% as much, or 0.12 bars. If this world's total atm is 0.8, your ppO is 15%
And so on.