Mass-transfer rates and accretion luminosities during mass-transfer phases for the three systems shown in Fig. 6. Accretion luminosities are shown as ranges going from the lower values given by strictly Eddington limited accretion rates, to the potential luminosities that could be achieved if the Eddington limit is ignored. The Eddington accretion rates for the metallicities log  Z = −2.5 and −3 overlap. This is due to the lower BH spin at log  Z = −2.5 compensating for the higher BH mass at log  Z = −3.