Scatterplot delineating the distribution of metallicity ([Fe/H]) against the median guiding radius (〈R_g〉) for our sample of disc stars. The colour gradient encodes the age in Gyr. Left panel: the marker size is modulated as a function of (△R)² (i.e. (〈R_g〉-〈R_b〉)²), as the y-axis of Fig. 13. Right panel: The marker size is proportional to (10 · 〈e〉)^3.5, where the minimum and maximum 〈e〉 values are 0.003 and 0.410 respectively. The marker size in each panel is arbitrary and slightly exaggerated to highlight each feature related to their movement, △R or 〈e〉. We do not attribute physical meaning to the sizes of the markers, but focus on showcasing where the most important differences lie. By doing this, we qualitatively verify that stars with lower metallicity tend to have higher △R, whereas stars with smaller 〈R_g〉 seem to have a slightly higher 〈e〉.