When it comes to saving an avatar, you are not facilitated to save an avatar from the game itself.
In this case the head must keep being a head with it's rectangular silhouette.
Also it will be necessity to have the latest version to have the best performance.
As the next step, you should open material and set Render Mode to: Opaque.
Although there are several options, they will not make much difference if you go for a change as well.