Line profile predictions for the high mass-loss-rate case Ṁ_g = 5.0 × 10^-5 M_⊙ yr^-1. The full black curve corresponds to the standard model with the inner radius of the gas shell R_i,g = 3 R_⋆ , the black extinction efficiency profile from Fig. 2 and ψ = 0.01. In all other models only a single property is modified. The dotted green curve (which coincides with the other curves) assumes R_i,g = 10 R_⋆ , the full blue and dashed red curves apply the blue and red extinction efficiency profiles from Fig. 2 and the dashed-dotted magenta curve assumes ψ = 0.001 (see Sect. 3.6 for more details).