Champion Textures bug

So first off let me say that I play League of Legend on a horrible old Macbook so I play on the lowest possible graphics settings with shadows and everything turned off. But there seems to be a bug that is interfering with my settings. When any champion changes their texture from their absolute original that they started with in the game such as using Kog' Maw's W or Nasus's ultimate, that new texture that the champion has for whatever amount of time is in the Very High character texture setting. Another example is evolving Kha' Zix's ultimate. Am I the only one experiencing this? It's not too big of a deal or game breaking but it lowers my frames in game as you could guess.