Over the subregion of (2.14) where $\ell\geq 2A^{-1/4}$, namely outside the curvature scale along $\mathfrak{D}_{1}$, the model metric $g_{\text{Taub}}$ is itself locally approximated by the flat model $g_{\text{flat}}$ (cf. Section 2.2) over $g_{a}$-balls of radius $\sim\ell(x)$: