Notes. Three groups of models are explored corresponding to variations in a R_CSM, Ṁ, and wind velocity profile. All models correspond to the explosion of a 15 M_⊙ star initially, evolved to core collapse at solar metallicity, and exploded to yield an ejecta with a kinetic energy of 1.2 × 10⁵¹ erg. The mass loss rate indicated in this table refers to the high-density CSM at the surface of the star, which drops rapidly to 10⁻⁶ M_⊙ yr⁻¹ beyond R_CSM (see Fig. 1). The wind velocity profile is characterized by parameters β_w and V_∞, and an adjustable base velocity V₀ to smoothly connect to the density at R_⋆. The next three columns indicate the CSM mass, optical depth τ_CSM, and the corresponding photospheric radius. For τ_CSM, we integrate from R_⋆ to infinity and adopt an opacity of 0.34 cm² g⁻¹. With this approach, the bulk of the optical depth arises from the denser, deeper regions near R_⋆. The last column indicates whether the HERACLES simulation of the model was post-processed with CMFGEN. Model mdot0p01/rcsm8e14 is a close analog of model mdot0p01/rcsm8e14/bw2/vinf5e6, for which we therefore skipped the calculation with CMFGEN.