Effective number of galaxies, N _eff, that would yield a constraint at or below a given L _wh,thr, for T = {150, 200, 300, 400, 600} K (STRICT + union mask). The rapid rise and saturation toward the parent sample size quantify the survey’s constraining power and directly underwrite Figure 2 via f ₉₅ ≃ 3/N _eff in the zero event regime.