I wonder if this is due to not using the native compositor which they are looking at fixing this year. See "Adding support for native OS compositors to WebRend

I wonder if this is due to not using the native compositor which they are looking at fixing this year. See "Adding support for native OS compositors to WebRender" at https://pcwalton.github.io/2018/12/07/plans-for-2019.html https://pcwalton.github.io/2018/12/07/plans-for-2019.html