Versions
Charm version 2.2.2
Minecraft version 1.16.5

Description
Items placed in the 2x2 crafting grid are not dropped if the player opens the 3x3 portable crafting, and then exits their inventory. This allows the player to carry 256 more items as long as they press the portable crafting button before closing their inventory.

Steps To Reproduce
Step 1.
Place any items in the 2x2 grid

Step 2.
Open portable crafting, then close your inventory

Step 3.
The items in the 2x2 grid will remain until the inventory is open and closed again, but can be perpetually done by opening portable crafting before exiting.