Significant FPS Drop when Moving Mouse over GUI Elements [Mac]

On a Mac, scrolling over GUI elements, in the World Outliner for instance, results in a significant frame rate drop.

Regression: No, occurs in UE4.14.3

Does not occur in Windows

1. On a Mac, open a Blank Blueprint Project with no Starter content.
2. Under Editor Preferences> Miscellaneous>Performance> select "Show Frame Rate and Memory
3. Return to Main Viewport and notice the frame rate in the upper right corner of the editor while moving the mouse around in the Main Viewport
4. Now scroll over GUI elements in the World Outliner
   RESULT: Frame rate drops to about half of what it was when moving the mouse in the Main Viewport
   EXPECTED: Frame rate to remain relatively the same whether in the Main Viewport or scrolling over GUI elements in the World Outliner and other menus.