This is an expected enhancement to the existing window splits. 

Presently, dragging the window to the left resizes the window to its half of the size and keeps it on the left portion of the screen, dragging it to the right does the same thing and keeps the window in the right hand portion of the screen. Similarly dragging the window to the top maximizes the window.

Could be added:

* Dragging right and left could be used to resize the window to 1/3, 2/3, 1/2, or percentage-based by popping out a context menu.
* Moving to the top/bottom could also be used to split the windows horizontally.  
*Moving the window to any of the corners could be used to maximize the window.

I didn't find any existing enhancement requests. I believe people will find this really useful when working with multiple windows. If this enhancement is not considered useful, my apologies.