Age validation with wide binaries from K. El-Badry & H.-W. Rix (2018) and D. Gruner et al. (2023). The gyrochronology ages inferred from our method for the wide-binary pairs agree well with minimal bias and a variance of ∼1 Gyr, independent of the differences in G_BP − G_RP between the binary pairs. More giant–main-sequence wide-binary pairs are needed to draw further conclusion on the cross calibration between [C/N] and gyrochronology. However, correcting for the bias where we subtracted 0.64 Gyr for [C/N] ages and −0.20 Gyr for gyrochronology ages, as determined in Figure 10, seems to achieve a better agreement between [C/N] and gyrochronology ages.