Photometric accuracy analysis: source integrated fluxes. Peak value (the mode) of the distribution of the relative discrepancy between measured (F_INT) and simulated $\left(F_{\text{INT}}^{\text{inj}}\right)$ integrated fluxes, as a function of the injected flux level $F_{\text{INT}}^{\text{inj}}$ (Group 1 left panel, Group 2 middle panel, Group 3 right panel). In all panels, the vertical error bars mark the interquartile range of the distribution within each level, while the vertical dashed red line reports the estimated flux completeness limit for the current group. The horizontal dashed grey line marks the equality between F_INT and $F_{\text{INT}}^{\text{inj}}$.