Left-hand panels: Evolution of the total gas mass (solid lines) and stellar mass (dashed lines) within the entire disc for the three feedback cases under analysis (i.e. ϵ_c = 0, 10⁻³, and 5 × 10⁻³, from top to bottom). The inset magnifies the terminal part of the stellar evolution lines in the top-left panel (the no-feedback case), where the curves overlap. The right-hand panels show the evolution of the M_BH/M_* ratio. Different colours indicate the various initial BH masses, following the same colour scheme used in Fig. 1. For reference, the Eddington-limited (‘EL’ in the figure) cases with M_BH(t_i) = 5 × 10² and M_BH(t_i) = 10⁵ and ϵ_c = 0 are included in the corresponding panel. The same symmetric logarithmic scale and linear threshold of Fig. 1 are applied to the x-axis in the left-hand column, whereas a full logarithmic scale is used in the right-hand column, with the origin set at t = 10⁻² Myr, approximately corresponding to the onset of the first SF episodes.