The Apple Pencil has the ability to move the cursor around and long press with BTT Remote, but that's pretty much it. The pencil isn't able to perform any kind of clicking. Having support for left clicking with the pencil would be great, even if the left click consisted of a double tap.
I would love to be able to assign the apple double-tap on the pencil (which swaps art devices/erasers in drawing programs) to an app function or keyboard shortcut.