Bang-Jensen–Yeo arc-partition conjecture for highly arc-connected digraphs

Let $D=(V,A)$ be a digraph. An arc-partition is a partition of its arc set into two parts, $A=A_1\cup A_2$, and a subdigraph is spanning and strong if it has vertex set $V$ and is strongly connected.

Bang-Jensen–Yeo's conjecture. There exists an integer $K$ such that every $K$-arc-strong digraph $D=(V,A)$ has an arc-partition

$$A=A_1\cup A_2$$

such that each of the subdigraphs $D_1=(V,A_1)$ and $D_2=(V,A_2)$ is spanning and strong.

This conjecture would imply Thomassen's good-pair conjecture by decomposing a sufficiently arc-strong digraph into two spanning strong subdigraphs. The source states that it is open; in particular, the minimum such $K$ is unknown.