Effective Knudsen number at the circularization radius (computed from Equation (B4)) as a function of specific angular momentum, for M_BH = 10⁻¹⁶ M_⊙. The hatched bands mark the excluded loss-cone (ℓ < ℓ_crit) and reflected (﹩\ell \gt {\ell }_{{\rm{\max }}}﹩) populations. The pileup enhancement ξ(ℓ) is sufficient to make Kn_eff < 1 for the bulk of the recycling population (ℓ ≳ ℓ_⋆ ≃ 12ℓ_crit), so most circularization radii are self-collisionalized. Only a low-ℓ tail (∼21%) remains in the formally collisionless “reservoir” regime; the additional mass needed to push these bins to Kn_eff ∼ 1 is ∼6 × 10⁻¹⁵ g and accumulates in only a few freefall times.