I grant that conformity does signal education of the norms. Which can be seen as signaling effort. But I expect it to be so noisy that it will have little predictive power.
As such, it is seen at both ends and provides little predictive power.
Agree. To take this a step further, I would say good programmers follow the style that exists in the codebase, if applicable, for consistency and therefore maintainability's sake.
It' doesn't necessarily mean they are a good programmer, but it means they are fairly meticulous, which can be a trait of a good programmer.
The "good"/experienced programmers are the ones that will break established styles to improve readability in corner cases, instead of following the rules blindly. On top of that, they've probably been doing it long enough they have their own preferences and idiosyncrasies, some of which may go against established styles.
On the flipside are the "bad" and new programmers, who don't really have their own style nor have learned an established one, so they just do whatever.
It's the average ones in the middle who only follow established styles that I would expect to be easy to pick out.
I think the value of standardization is much higher than the value of "break[ing] established styles to improve readability in corner cases". I just find the marginal value of these little stylistic improvements to be extremely low, and the value of code looking quite similar everywhere to be quite high.