It currently picks the largest topmost window (correct me if I'm wrong),
which can be static UI layer. (Youtube Video, Infinite painter, Ciry Racing 3D, etc).

It should take the updates into account so that it can pick
the most efficient one to be used as overlay/underlay.

If this isn't good enough, we'll look into other approaches,
such as prioritize a layer for SurfaceView, and/or interoduce API/flag.