Likelihood function over θ = [ξ(l_p, GRG),Δξ, b_ν, ref, σ_ref, ζ, n_GRG], based on 2685 projected lengths and redshifts of giants up to z_max = 0.5. We show all two-parameter marginals of the likelihood function, with contours enclosing 50% and 90% of total probability. We mark the maximum likelihood estimate (MLE) values (grey dot) and the likelihood mean values (grey cross). The one-parameter marginals again show the MLE (dash-dotted line), a mean-centred interval of standard deviation–sized half-width (hashed region), and a median-centred 90% credible interval (shaded region).