Top panels: Average transverse momentum as a function of the average charged-particle density, and predictions using the \py and \ep models. The model calculations and fits (shown with the red dashed lines) correspond to the flattenicity-dependent measurements. The fit uses the $a-b\times(c-x)^{-1}$ parameterization, where $a,b$, and $c$ are free fit parameters. Bottom panels: Data-to-fit ratios for both the flattenicity- and multiplicity-dependent measurements. The multiplicity-dependent results are taken from Ref. . The statistical and systematic uncertainties are shown with lines and empty boxes.