If a player has a larger backpack than a regular player and then their backpack shrinks, the items in the backpack will be dropped on the ground. It would be beneficial to add a warning when opening the backpack, before dropping items, stating that the items in the backpack will be dropped. The player would need to confirm by typing the command again (e.g., "backpack") to proceed with dropping items.

Alternatively, another option would be to gradually transfer the items from the backpack into the player's inventory when opening it, allowing the player to retrieve them. However, if the player has excess items in the backpack, they would not be able to open it until they reduce the number of items.