With the bundle features implemented for shulkers, right-clicking the result item in a crafting table, the ingredient items needed to craft will not be used up. Removing and replacing the ingredient items will allow you to right-click the result item again, resulting in a duping method.

Confirmed, one has to take a box in the cursor, and click on the result slot with the box, that will obtain the craft result without consuming the ingredients.

Confirmed, one has to take a box in the cursor, and click on the result slot with the box, that will obtain the craft result without consuming the ingredients.

Can confirm still now (version 1.4.0-1.20)