The doubling conjecture for noncollapsed RCD spaces

Let $X$ be a noncollapsed $RCD(K,n)$ space with nonempty boundary $\partial X$. Doubling conjecture. The doubled space $\operatorname{Dbl}(X)$ satisfies the condition $RCD(K,n)$. This is presented as a simpler special case of the preceding gluing conjecture. The supplied text gives no resolution status beyond its conjectural formulation.