Since the furnace and alloy smelter don't take weighted outputs (eg. 50% chance of one output, 50% of another) what I suggest is adding a furnace like machine that acts as a still in that it allows pack makers to define weighted outputs. eg. suppose I added a wine bottle via another mod and wanted to distill it to brandy in a minecraft like way. With this suggestion implemented, I could define a recipe where say 70% of the time the output of the still is a glass bottle and 30% of the time it's a bottle of brandy.