Feature Request: Hide tool window's title bar, except when multiple tabs are opened.

I'm loving the new UI.  Well done.  Following the new UI theme of hiding the title bar increasing usable space, would it be possible to hide the title bar for the tool bar if a single tab is open?  I don't have multiple tabs open so for my use case it's excess whitespace that isn't needed.  This title bar is taking up precious screen real estate.

In the example picture I already know the Debug tool bar is open because the tool window bars has Debug highlighted.  The title bar is redundant and takes up valuable space.