Left panel: comparison of the α_ml values obtained in the GS98 scenario (black dots) with those from Viani et al. (2018) (blue dots). The values from Viani et al. (2018) were offset by 0.4 to match the solar-scaled α_ml of the GS98 scenario. The green solid and blue dashed lines are the LOESS smoother for GS98 and Viani et al. (2018) datasets, respectively. Right panel: boxplot of the Viani et al. (2018) results in the metallicity bins adopted in the present work.