Whether the compositor should checkerboard layers that are rendered to offscreen bitmaps. This can be useful for debugging rendering performance.
Render target switches are caused by using opacity layers (via a FadeTransition or Opacity widget), clips, shader mask layers, etc. Selecting a new render target and merging it with the rest of the scene has a performance cost. This can sometimes be avoided by using equivalent widgets that do not require these layers (for example, replacing an Opacity widget with an widgets.Image using a BlendMode).
final bool checkerboardOffscreenLayers