Wiring a crossing for automatic polarity control requires 2 Frog Juicer circuits. (Two single Frog Juicers, one dual Frog Juicer, or two circuits from a Hex Frog Juicer.)
Two of the frogs diagonally across from each other can be un-gapped. The other two frogs need to be gapped and the polarity controlled with each frog connected to its own auto-reverser circuit.