[Mg/Fe] vs. [Fe/H] for our sample stars: 1D LTE, 1D NLTE, 3D LTE, and 3D NLTE abundances are displayed according to the legends; all panels are built with [Fe/H] under 1D NLTE. The symbols representing the dwarfs are size-coded according to their ages. As a reference, stars classified as the in situ populations Splash (red) and Erebus (turquoise), and the ex situ population Gaia-Enceladus (grey) in Giribaldi & Smiljanic (2023) are plotted. The solid red, dashed black, and solid black lines display the LOWESS regressions. The shades display 20 to 80% quantiles. Bottom right panel: only dwarfs are displayed, as only these have 3D NLTE corrections. They are colour-coded according to age. Other panels: precision sample I (only dwarfs) has no colour-coding. The Precision sample II and Gaia-ESO sample are colour-codded according to log g. Their symbols follow the legends in the plots. The panel 1D NLTE displays the error bars of the stars in Precision samples I and II with errors larger than 0.14 dex.