overlayRepaintBoundaries property
Whether the harness Overlay wraps each entry in a repaint boundary, as
every production host does (buildTuiRoot takes the Overlay default).
True by default so the cached-blit path a real app takes is the path under test. Pass false only for a test that must observe the bare paint walk — a boundary-counting assertion, or a fixture that mounts its own Overlay and would otherwise measure the harness's boundaries too.
Implementation
final bool overlayRepaintBoundaries;