Based on the XRD of the freshly measured cluster centroids, both RGB and compositional centroids within each cluster show same type of XRD patterns, and differing XRD patterns between the clusters, which is expected to lead to stability differences: Cluster 1 > Cluster 0 > Cluster 2. This is in line with the observations from the RGB data. The XRD analysis of the cluster centroids helps in this case also revealing and explaining a potential source of false positives in the examined compositional region, because cluster 2 compositions with high content of nonphotoactive δ-CsPbI3 are not likely to result in high-performing solar cells. This example illustrates that the spot-checks of cluster centroid samples serve as an effective route to understanding the main features of the investigated material domain when it is not desirable to expose all the samples to extended characterization.