Same as in Fig. 12 but for bubble models with lower absorptions as indicated in the respective panels. Filled circles give the positions of the bubbles with homogeneous WR composition (ω = 0 ) that comply with the constraints from Fig. 8 with the appropriate N_H value. The green lines enclose the corresponding positions if in the outer bubble parts the WR mixture is replaced by PN mixture (ω = 0.03, left panel, and ω = 0.02, right panel).