log(Age_w/yr) as a function of log(SFR/M_⊙ yr⁻¹) observed for BGGs in the S-I to S-V subsamples (KDE density map, shaded grey area). Red and green contours represent stellar age vs. stellar mass predictions by H15 and Magneticum. Median stellar age values in specific mass bins are indicated by black points (COSMOS), green diamonds (Magneticum), and red squares (H15). In the lower-right panel, we present the relationship between stellar age and stellar mass for a combined sample of BGGs within S-II to S-V. The vertical grey line marks log(SFR/M_⊙ yr⁻¹) = −5.97, the observed SFR threshold. In models, galaxies with SFR = 0 have been adjusted to the observed SFR threshold. For star forming BGGs, log(Age_w/yr) shows a negative correlation with SFR with no significant evolution with increasing redshift, which is more pronounced in the observations compared to H15 and Magneticum simulation predictions.