the math could only ever be a factor in your decision.

Sure. I don't think this is inconsistent with what I was suggesting, which was really just that that the math could start the process off.

For humans, the process by which decision-making is done, has consequences for how it's implemented, and for the person's experience and satisfaction regarding the decision itself.

All of which I agree with; but again, I don't see how this rules out learning to use math better.

Mostly, my experience is that people are generally better off with a 50% plan executed 100% than a 100% plan executed 50%.

Fair enough. The examples I'm thinking of typically involve "owned" decisions that are more accurately characterised as 0% plans (i.e. do nothing) or -X% plans (i.e. do things that are actively counterproductive).

Now I try to plan just enough to get S1 buy-in, and start taking action so I can get feedback sooner.

1. How do you decide what to get S1 to buy in to?
2. What do you do in situations where feedback comes too late (long term investments with distant payoffs) or never (e.g. ethical decisions where the world will never let you know whether you're right or not).

P.S. Yes, I'm avoiding the concrete example request. I actually have a few, but they'd take longer to write up than I have time available at the moment, and involve things I'm not sure I'm entirely comfortable sharing.