2 separate displays in one window on MAC causing FPS drop

Ever since I alt + entered to get rid of the 1/4 screen problem I lost around 80FPS.

Today I've realized that there are 2 windows of the same game open, the standard full screen and the 1/4 screen within the same window.

I noticed this when a game ended and I saw a separate window slightly delayed still in the game screen and also when I alt +tabbed. Riot please show Mac client some love and resolve this issue.

Also note: When I am in league client (yes, client not the game) my visuals for volume up and down are not centered they are fit for a different screen resolution.