The plugin does not currently support crafting more than one item at a time. However, it would allow you to enter ingredients that would craft more than one item in a regular crafting table. Even so, it would still only craft one item. Thus it would allow you to create very expensive recipes without warning. For example, if you placed 64 stone blocks into the crafting block, it would not craft 64 buttons, it would craft only one, but consume 64 stone blocks to do so.

This release prevents this from happening by refusing to accept any recipe that has a stack of items in any crafting slot.