Same as Fig. 2 but assuming BH masses and accretion rates from Lupi et al. (2024b). We selected here the combination of M_BH, f_Edd, a_• showing the highest K_X correction among the ten solutions with the highest probability over the 32k samples. Bolometric corrections are corrected according to the predicted bolometric luminosity of each source. Nearly all systems allow for spin configurations consistent with the current X-ray non-detection.