Add: Configurable cooldown for stress SAC rate

[Rolf-Smit]

[pabdakine]

Definitely favor this, as it's most realistic. I plan my CCR BO with an average rate for the first 10 mins and another thereafter. Currently I have to manually compute the quantity for the gas used during the transition.

I suggest a similar approach with an effective average initial rate, rather than linearly interpolating between the stressed and normal SAC values. My personal observations are that people stay stressed, but something finally registers in their brain and they calm down fairly quickly at that point.