Four-value CM conjecture for infinite-order meromorphic functions

Let $f$ and $g$ be two distinct transcendental meromorphic functions of infinite order, and let $a_1,a_2,a_3,a_4$ be four distinct values in the extended complex plane. Four-value CM conjecture. If $f$ and $g$ share $a_1,a_2,a_3$ IM and $a_4$ CM, then they share all four values $a_1,a_2,a_3,a_4$ CM. This extends the corresponding finite-order result and asks whether the weaker IM/CM sharing hypothesis forces complete CM sharing in the infinite-order case.