Mass difference between the BH masses M_BH; noSF – obtained from the simulations without SF (noSF, solid lines) – or M_BH; Tf – from simulations without SF and with an increased temperature floor (Tf, dashed lines) – and the reference masses M_BH. The same x-axis and colour-coding as in Fig. 2 are used. The upper panel refers to the suite with M_BH(t_i) = 5 × 10² M_⊙, whereas the lower panel refers to the suite with M_BH(t_i) = 10⁵ M_⊙.