Comparison of the derived stellar abundance ratios from the final X-shooter stellar sample with reliable [Mg/Fe] and [Ca/Fe] abundances, colour-coded by the origin of the adopted input [α/Fe] parameter: from Gaia DR3 (blue) or empirical approach (red). Left and middle panels: [Mg/Fe] and [Ca/Fe] as a function of [Fe/H], respectively. Right panel: direct comparison [Mg/Fe] vs. [Ca/Fe],