Left: shift of binary systems with q = 0.75 in the CMD relative to the single-star sequence of R. Liu et al. (2025). For twin binaries (q = 1), the color index is unchanged and the combined magnitude becomes brighter by 0.75 mag. Right: impact of enlarged absorption (A_V = 0.5 relative to A_V = 0.23 mag) on PARSEC 2.0 isochrones with star-by-star derived extinction (J. A. Cardelli et al. 1989; J. E. O’Donnell 1994), calculated via the CMD 3.8 interface (http://stev.oapd.inaf.it/cmd), R_V = 3.1.