I'm a little confused. Are you saying that this method helps you feel better about the things you think about, or that it helps you make better decisions? Or am I missing the point entirely? Maybe it would help me if you had an example of how you thought before using this method, and how the method would improve upon the situation.
I'd say that the most direct result is that it helps me feel better -- it definitely seems more like an emotional mind-trick than a tool for acquiring true beliefs, and its primary benefit is to help relieve anxiety, whether results-related or social-related.
I feel that I should be able to come up with a concrete example here, but I can't (yet.)
I do the same thing, I think. A baseline of "do nothing" is an emotionally neutral thing to compare your actions to, and accurately describes what you're probably getting done when you instead try to think of the best way to do something. But it took me a long time to get that.
If I'm reading this right, your hesitation is nearly the shape of an anxiety attack - it's a "meta-analysis lockdown", though not quite a "recursive meta-analysis meltdown". When you don't get that obvious physiological feedback flaring up, it's harder to recognize the similarity, unless it gets extreme. I hope it doesn't feel like too personal a question, but would you characterize yourself as having had an anxiety disorder? You mention the lockdown in social situations, where this is most common. But I think that the problem is the same however mild, and the solutions too.
When I'm relaxed enough to think in sentences and this happens, I stop and ask myself why I'm actually worried. For tasks, I usually notice then that my real worry isn't that I'll do "just ok", but that I won't even complete the given task! My brain remembers failing to finish things all too well, and the reason that happens not well enough. How strange, that the anticipation of a problem can cause the problem! I don't know if the same conditioned fear of total failure was your challenge as well, or what other things cause perfectionism.
I couldn't think clearly about this mental fog until I had an essential insight. Once I acknowledged that not completing the thing was my real fear, I considered this "worst case" as a real choice, possibly a good choice! Or perhaps, no choice at all. I retrained myself to really take it seriously by doing nothing on purpose.
This is an extreme example, and probably sounds crazy, because it was. One of the many things that triggered anxiety attacks for me was the realization that I was going to be late to work, unless I skipped breakfast. Another trigger was skipping breakfast. Working late to catch up caused me to get home late, often missing dinner, and getting poor, insufficient sleep. And my brain demanded a perfect solution to all parts of the problem, which was the real problem. When I realized that, the rest became clear. I had a leisurely breakfast, strolled to work late, and had a talk with my boss, explaining the whole thing. We made a deal that I could arrive between 9 and 10 with no questions asked. I loaded up on frozen dinners. After a few months, that trigger dissolved.
In an alternate universe, I might have gone to office hours when I was a student. Or slept and socialized instead of trying to catch up on homework every waking moment. In an alternate universe, a socially challenged perfectionist might intentionally say something unimpressive to some people they wish to impress, just to feel that the world won't then come to an end.
My actual feat was not changing my belief that I must accomplish perfection to avoid failure, not quite. On the surface, that's what a character in MoR would call "learning to lose". But really, learning to lose is accomplished by tabooing the words "lose" and "fail", and seeing what outcome you really fear.
TLDR: Thinking in abstract terms about outcomes can be helpful, and having a default outcome that corresponds well to over-analyzing is great. But you may have trouble doing this at all, or at least getting "correctly weighted outcomes" if you don't figure out what in your beliefs or values is really causing the heavy analysis. And that belief or value might be worth changing!
I sometimes feel negative emotions at the thought that the course of action that I am taking isn't even close to the optimal course of action -- that a more effective mind could sort through whatever situation I'm currently having difficulty with and craft a plan that was much more likely to succeed than any of my own. In short, I feel inept in comparison to the better minds in the space-of-all-possible-minds, and so I experience undue hesitation while I'm trying to figure out the correct action to take. Of course, good planning often leads to better results, but this behavioral pattern has a significantly negative effect in situations (especially social ones) where I need to make a decision quickly.
I've found that it helps me think more rapidly and clearly if I think in terms of which of the possible actions that I've thought of will produce the greatest positive difference in net expected utility in comparison to doing nothing. Once I come up with a course of action, I no longer feel a sense of paralysis at how inept my decision-making skills must be compared to much better minds than my own, which saves a certain amount of mental processing power and emotional effort which can then be used for other things. Doing this also helps to prevent panic and the like from springing up because I'm not thinking in terms of whether I can succeed or not, but sorting through which actions maximize my chances of succeeding out of the set of actions that I've currently thought up.
I feel like I've written less than I think that I've written -- that people may not get much out of this post because they haven't actually shared my brain with me, and I've done an inadequate job of deconstructing my thoughts when I've put them to paper. If this is correct, please tell me and I can try to elaborate.