“Hockey-stick” relation adapted from McGuire & Hapke (1995), Fernando et al. (2016), and Souchon et al. (2011) for all ROIs and for three inversion configurations: (a) the reference four-parameter inversion, (b) the six-parameter free-SHOE inversion, and (c) the fixed-SHOE inversion with (B₀, h) = (1.59, 0.097), following the literature-based prescription of Li et al. (2013). Data points represent posterior medians, and error bars show median absolute deviations. The colors follow the ROI definitions in Fig. 1.