Same as Fig. 16 but for the Tmin (left) and Tmax (right) setting. The burst is the same for both. The plot shows that the dust distribution strongly imprints the afterglow. For denser and more extended envelopes, the MIR/FIR afterglow can be significantly longer. Horizontal lines indicate the times when the peak is reached (white triangles), when 80% of the energy is released (black dots), and the time when the flux density is back at 1.25 × L_pre(λ) (gray).