Also - can be good to tell contractors up front that you're planning to get 2-3 quotes on whatever job it is. That way they're less likely to pull something crazy if they know that you're shopping around a bit
You say:
Another problem is whether the "winning" approach might come from deeper searching along the existing paths, rather than broader searching in weirder areas. In that case, it could maybe still make sense to proliferate sub-approaches under the existing paths. The rest of the points (especially (4) below) would still apply, and this still relies on the existing paths being... broken enough to call "doom", but not broken enough to try anything too different. This is possible.
This seems pretty plausible to me, and makes me think that people ...
just noting that the hyperlink for "nowcasting" is broken