Hanauer et al.'s feedback arc set conjecture for strongly connected degree-five oriented graphs

Let $D$ be a strongly connected oriented graph, and let $\Delta$ denote its maximum degree. A feedback arc set is a set of arcs whose deletion makes $D$ acyclic; let ${\rm fas}(D)$ denote its minimum size. Let $n$ be the number of vertices.

Hanauer et al.'s conjecture. If $\Delta\leq 5$, then

$${\rm fas}(D)\leq \frac{2n}{3}.$$

This is a stronger-looking bound for strongly connected oriented graphs than the general degree-five multigraph conjecture. The supplied excerpt does not state whether this conjecture has been resolved, so its database status remains open.