Average ratio between the BH formation time (t_form) and the total age of the galaxy (t_age) for each (α, β) model (see the colorbar). The y-axis shows the star formation parameter α, and the x-axis shows the mass-radius relation exponent β. Dark purple regions indicate very early seed formation (t_form ≈ 0.1 t_age), while yellow regions indicate very late formation (t_form ≈ t_age).