I would like to use Cura's mold feature to print an object in PVA. How do I approach this? I've tried selecting the object and setting it to "Print Selected Model With: Extruder 2: PVA BB 0.4" and then clicking "Mold" in Special Modes. But when I hit "Prepare," I get the original object sliced as usual, not the negative. If I have the model set to "Print Selected Model With: Extruder 1: PLA AA 0.4" the mold mode works correctly, no problem.