Mass-loss rates as function of luminosity for samples of SMC (this work), LMC (Hawcroft et al. 2024a, Brands et al. in prep.), and MW stars (Hawcroft et al. 2021). The dotted lines indicate the linear fits to the data for each of the metallicities, with the shaded region the 1 σ confidence interval on the fit. Stars with poor spectral fits, marked with a red border, are left out the linear fit here. The parameters of the fit are listed in Table F.1.