The RenderOpacity object will not emit a layer when the opacity is 0 or 255. If that is the static opacity then it might make sense, but when it is the value during an animation, this causes the layer tree to drastically change configuration on each frame.

While this could potentially result in a hit if the tree needs to be constantly reconstructed, an even bigger hit happens because the change of identity of its own layer as it moves from a partial value to either 0 or 255 and back again means that the cached information at the engine level needs to be discarded and then re-rendered.

The layer should absolutely be left intact even for opacity values of 0 or 255 during an animation.