If you change your pick block button, some creative tweaks in the inventory doesn't work:

• Unable to duplicate a stack of items in the 'Search Inventory" tab
• Unable to duplicate items on a range of cases when holding the button (I don't know how to explain it, usually if you hold the middle-click button and move your mouse around it creates stacks of items in the cases you flew over)

There might be some more but I didn't uncovered them.

To reproduce, simply change the pick block button to an other key and test what I've said up there!