Personally, I'd want it at the neighborhood level. Though there may not be enough data within a reasonable timeframe at that level, it can at least be reasonably compared to a broader index for the city.
I don't think you get much at the zip code level that you wouldn't get at the Metro level.
The probability of a second reduction is also too simple. It makes no account for the market turning positive. That's precisely the error in modelling that failed us on the upswing: the assumption that present trends will continue.
A pricing heatmap in 10% bands would be pretty good I think. Houses next to each other tend to be more or less the same value with a few edge case scenarios -- the farm as noted in the other reply to this.
I don't think you get much at the zip code level that you wouldn't get at the Metro level.
The probability of a second reduction is also too simple. It makes no account for the market turning positive. That's precisely the error in modelling that failed us on the upswing: the assumption that present trends will continue.