It should be about using thinking techniques that help one win, whatever those turn out to be.

Absolutely. And rationality is the means by which we evaluate, implement, and update those techniques. The "means by which" in the previous sentence is what rationality is.

But the process stuff is here a means to an end (to be changed, if it turns out that our processes don't help), rather than a reified end in itself.

You're talking here about specific processes for achieving specific wins. I'm saying that rationality integrally involves the higher-level general processes by which we determine which techniques (low-level processes) to use, how to evaluate the results of using them, how to modify them based on experience, etc.