Duncan–Steingrímsson's bistatistic equidistribution conjecture for 021-avoiding ascent sequences

An ascent sequence of length $n$ is a nonnegative integer sequence $x=x_1x_2\ldots x_n$ with $x_1=0$ and $x_i\leq \operatorname{asc}(x_1x_2\ldots x_{i-1})+1$ for $1<i\leq n$, where $\operatorname{asc}(x_1x_2\ldots x_{i-1})$ is the number of ascents in the prefix. Let $\mathcal{A}_n(021)$ be the set of ascent sequences avoiding the pattern $021$, and let $S_n(132)$ be the set of permutations in $S_n$ avoiding $132$. For a sequence $x$, let $\operatorname{rlm}(x)$ be the number of right-to-left minima, meaning indices $i$ such that $x_i<x_j$ for every $j>i$. Duncan–Steingrímsson's conjecture. The bistatistic $(\operatorname{asc},\operatorname{rlm})$ has the same distribution over $\mathcal{A}_n(021)$ and $S_n(132)$. This refines the known equidistribution of the ascent statistic alone and relates two Catalan families; the source provides no resolution of the conjecture.