Late-time modeled (SSA-only) flux evolution at ν = 4.93 GHz of a shockwave interacting with a torus-like CSM with density profiles characterized by a single power law, ρ_csm  ∝  r^−s, as shown in Figure 6. From left to right, each panel corresponds to the flux evolution for s = 0, 1, and 2, highlighting how varying s alters the predicted flux evolution. We plot the late-time VLBI flux measurements at 4.93 GHz from Table 4 as black squares. The best-fit model, corresponding to the required filling factor to scale the late-time fluxes, is indicated by a dashed black line. The maroon, red, orange, and yellow lines on each panel represent filling factors f = 1.0, 0.1, 0.01, and  0.001, respectively, as labeled in the middle panel. Residuals of each fit are provided in the lower panels, zoomed in around the time of our observations. The figure assumes E_k = 5 × 10⁵¹ erg, M_ej = 5 M_⊙, D_L = 23.5 Mpc, v_w = 1000 km s⁻¹, α = 1, ϵ_B = 0.1, and p = 3.