Fraction of detected binarity as function of Δv_lim. The solid black line in the left panel shows the B5–9 supergiants, and the right panel is the same, except for AF supergiants. The dashed red lines show the simulated binary fraction assuming an intrinsic binary fraction on the main sequence of 75 ± 10% – to roughly match that of Villaseñor et al. (2025) – which was evolved to remove binary systems that would have since interacted based on the current sizes of the stars. The solid red lines show the bounds of the assumed uncertainty on the intrinsic multiplicity fraction.