Rhoades–Wilson double superspace Vandermonde conjecture

For $1\leq k\leq n$, let $\mathbb{V}_{n,k}$ be the smallest subspace of $\Omega_n[y_1,\dots,y_n]$ containing the superspace Vandermonde $\delta_{n,k}$, closed under $\partial/\partial x_i$ and $\partial/\partial y_i$, and closed under each polarization operator

$$y_1\frac{\partial^j}{\partial x_1^j}+\cdots+y_n\frac{\partial^j}{\partial x_n^j},\qquad j\geq1.$$

Let $SDR_n$ be the superspace diagonal coinvariant algebra. Rhoades–Wilson double Vandermonde conjecture.

$$\operatorname{grFrob}(\mathbb{V}_{n,k};q,t)=\Delta'_{e_{k-1}}e_n,$$

and the composite map

$$\bigoplus_{k=1}^n\mathbb{V}_{n,k}\hookrightarrow\Omega_n[y_1,\dots,y_n]\twoheadrightarrow SDR_n$$

is bijective. The source notes that the first assertion is known at $t=0$, while the corresponding coinvariant statement remains open.