When crafting an item with 2 of all ingredients, shift clicking on the crafted item will cause your inventory to be filled with stacks of the crafted item. This is consistenly reproducible on a server running ATM-9-0.2.46

Crafting one item works, although the item remains visually in the slot even after being taken out.

When crafting two items, the inventory is filled and the crafting ingredients are not used up while crafting.