Simulated observed lightcurves and spectral peak temperature evolution of SN SBO and subsequent cooling emission in dense CSM shell for different r_out (top left), χ (top right), M_CSM (bottom left), and v_sh (bottom right). In each panel, the upper subpanel presents the observed lightcurves in both the bolometric band (solid lines) and soft X-ray band (dashed lines; 0.5–4 keV), while the lower subpanel shows the evolution of the observed spectral peak temperature. Each panel shows four choices of the corresponding parameter, including the fiducial values of r_out = 3.2 × 10² R_⊙, χ = 0.1, M_CSM = 3.2 × 10⁻⁴ M_⊙, and v_sh = 0.15c.