On nonemptiness of Newton strata in the $B_{\mathrm{d}\mathrm{R}}^{+}$-Grassmannian for ${\mathrm{G}\mathrm{S}\mathrm{p}}_{2n}$

We build upon our previous work to study the Newton stratification on the $B_{\mathrm{d}\mathrm{R}}^{+}$-Grassmannian for ${\mathrm{G}\mathrm{S}\mathrm{p}}_{2n}$. Our main result gives an explicit classification of all nonempty Newton strata associated to a Frobenius-conjugacy class satisfying certain conditions on the Newton polygon.