A fixed horizontal window $M_G \in [10.0, 10.3]$ integrated over the whole $2.2 < G_{BP}-G_{RP} < 2.8$ box measures only a $0.9\%$ deficit (bootstrap CI68 $[-0.2, 2.1]\%$, parametric-bootstrap p = 0.20) on the same data: because the narrow gap is sloped and the main-sequence ridge sweeps $\sim 2$ mag across the box, whole-box window statistics structurally dilute this feature; per-strip measurement is required.