The most important non-constant features are located in the pre-edge region for the four lighter metals (Ti, V, Cr, Mn), in agreement with known qualitative trends . The quadratic character of Ti and V pre-edges as the second-most important features perfectly line up with domain knowledge that the intensity of a pre-edge peak is critical for coordination classification for lighter metals; Cr also has multiple higher order coefficients ranking as important in the pre-edge region . We also see that pre-edge features remain important features for Mn, Fe, Co, Ni, and Cu, consistent with earlier studies . Still, for the four heavier metals (Fe, Co, Ni, and Cu), the polynomial-featurized models primarily rely on absorption in the edge and post-edge regions. These findings have particular relevance in identifying the minimum energy range for an experimental scan in order to identify the coordination number an absorbing atom.