Selected residual maps for the M1 reconstruction, shown for the data bin with cos(θ_w′) ∈ (0.9, 1.0] (ct_idx = 7 in Fig. 4). Top: FRONT events. Bottom: BACK events. The energy bins are the same as in Fig. 4 but shown from left to right: 1.00–1.78 GeV (left), 10.0–17.8 GeV (middle), and 178–316 GeV (right). The maps are clipped to the 99.9th percentile of the residual amplitude in their respective energy bin. For comparison, Fig. D.2 shows the distribution of photon counts in the selected data bins.