While the "Spinning Dust" hypothesis (electric dipole radiation from rapidly rotating nano-grains) explains the general presence of Anomalous Microwave Emission (AME), the observed peak frequency of this emission varies significantly (from $\sim 20$ GHz to $>40$ GHz) across different environments in ways that standard models fail to predict. Theoretical models based on environmental conditions (radiation field stiffness, gas density) often predict peak frequencies that disagree with observations, and the correlation between the peak frequency and local ISM parameters is weaker or different than expected, suggesting an unknown mechanism governs the grain rotation distribution (Planck Collaboration 2014; Hensley & Draine 2017).