Unimodality conjecture for stable weight multiplicity polynomials of $\mathfrak{spo}(2n,M)$

Let $P^+(n,m)$ be the set of dominant weights, and let $K_{\lambda,\mu}^{\mathrm{stab}}(q)$ denote the stable $q$-analog of the weight multiplicity for the orthosymplectic Lie superalgebras considered in the source. Unimodality conjecture. Given $\lambda,\mu\in P^+(n,m)$, the polynomial $K_{\lambda,\mu}^{\mathrm{stab}}(q)$ is unimodal. This conjecture is motivated by computations for orthosymplectic Lie superalgebras and remains unproved in the source.