Local models are schemes, defined in terms of linear-algebraic moduli problems, which
are used to model the étale-local structure of integral models of certain $p$-adic PEL Shimura varieties defined by Rapoport and Zink. In the
case of a unitary similitude group whose localization at ${ \mathbb{Q} }_{p} $ is ramified, quasi-split $G{U}_{n} $, Pappas has observed that the original local models are typically
not flat, and he and Rapoport have introduced new conditions to the original moduli
problem which they conjecture to yield a flat scheme. In a previous paper, we proved
that their new local models are topologically flat when $n$ is odd. In the present paper, we prove topological flatness when $n$ is even. Along the way, we characterize the $\mu $-admissible set for certain cocharacters $\mu $ in types $B$ and $D$, and we show that for these cocharacters admissibility can be
characterized in a vertexwise way, confirming a conjecture of Pappas and
Rapoport.