The locking feature only recently became officially available in vanilla, and before that I would group the items I needed at the bottom.
With the system that lets you lock any number of items from the top, items are placed in order from the empty slots at the top, so there was the issue that slots that had already been used up would be filled with unnecessary items and locked in.
Still, playing with the locking feature was more efficient, so I had to get used to it, but it's very helpful that you can now set any lock slot you want. This is a good update.