Radiative-to-gravitational force ratio (Γ) vs gas-to-dust mass ratio for dust models fitting the polarisation observations. Squares and circles denote inner and outer regions (R ≶ 1.6R₈₈₇ from Khouri et al. 2024); colours indicate grain sizes. Five zones are shown, based on physical viability: (A) Γ > 1 but > 100% elemental depletion is impossible; (B) Γ < 1 and > 100% and depletion is impossible; (C) < 100% depletion but Γ < 1, representing insufficient radiation pressure; (D) Γ > 1 with high but possible depletion inconsistent with observations; and (E) Γ > 1 with observed depletion levels, the ideal wind-driving zone. The horizontal line marks Γ = 1.