Density profile encountered by the shock as a function of time for different expansion parameters m (including m = 0.83 as in Tatischeff 2009, a model applied to SN 1993J). We assumed Ṁ_RSG = 10⁻² M_⊙ yr⁻¹, u_w = 100 km s⁻¹, and V_s, 0 = 10⁴ km s⁻¹. The average density ρ₀ obtained by Bostroem et al. (2023) is also displayed, as well as the best-fit density profile from the r1w6b model in Jacobson-Galán et al. (2023). The grey-shaded region excludes the times not considered in our discussion on the SN energy budget.