Completeness of the BLOeM dataset with respect to the underlying Gaia catalogue. Left: CMD showing the underlying Gaia catalogue used to choose the BLOeM sample (black dots). Three evolution tracks computed by Schootemeijer et al. (2019) and Hastings et al. (2021) with the MESA stellar evolution code (see Sec. 5.4) for M_ini = 7.9, 13.8, and 24 M_⊙ are plotted. The tracks were adjusted to the SMC distance and an average reddening and extinction (see text for details). BLOeM targets are encircled with blue (M_ini/M_⊙ ≳ 14; born as O-type stars) and pink (8 ≲ M_ini/M_⊙ ≲ 14; born as B-type stars) circles. Right: Magnitude distribution of the subsamples, along with completeness fractions for the two subsamples with respect to the underlying Gaia SMC catalogue.