In the Copy From window change the size of the bottom

In the Copy From window change the size of the bottom left pane to much smaller or make the top left much larger

Currently the way it is set, when you open the tree, the top left window is very small. You have the ability to drag the window larger but you must do this every time you open the Copy From. It would be nice if either the window was larger by default or the user could set the default size.