also anecdotal....but I have correctly called many a state house race based upon “earned signs” ie, signs placed in the yards of voters....as opposed to “bandit signs” placed in right of way or vacant lots.
so, what you report is relevant. it really is. maybe not decisive...but very relevant.
A person with a scientific mind could probably find a way to make something out of the dispersion and number of signs for this or that candidate.
But, like you, I think they are a hint about what is going on.