Pappas's spin local model flatness conjecture for ramified unitary groups

Let $M^{\rm naive}_I$ be the naive local model for a ramified unitary group, and let $M_I$ be the closed subscheme defined by conditions a)--f), including the wedge conditions and the Spin condition. The schemes $M_I$ and $M^{\rm naive}_I$ have the same generic fiber.

Pappas's spin flatness conjecture. The scheme $M_I$ is flat over $\mathcal O_E$; equivalently,

$$M^{\rm loc}_I=M_I.$$

This strengthens the wedge-condition conjecture for general parahoric index sets by imposing the Spin condition. The source presents it as a conjecture, and no resolution is supplied here.