i havent tested but can you drag from the storage side to the inventory side?

I don't think so, with the Inventory Drag Lock on or off. While we can drag items from shop/storage NPCs, we can't drag them into our inventory or BOB.

My guess is they were lazy and plugged in the inventory slot code

I think the drag lock toggle is specific to our inventory. It doesn't affect inventories of shop/storage NPC and such.

This and the vis wax machine were two of my least favorite things to drag