*`paintWhenInitiallyHidden` boolean (optional) - Whether the renderer should be active when `show` is `false` and it has just been created. In order for `document.visibilityState` to work correctly on first load with `show: false` you should set this to `false`. Setting this to `false` will cause the `ready-to-show` event to not fire. Default is `true`.
*`titleBarOverlay` Object | Boolean (optional) - When using a frameless window in conjunction with `win.setWindowButtonVisibility(true)` on macOS or using a `titleBarStyle` so that the standard window controls ("traffic lights" on macOS) are visible, this property enables the Window Controls Overlay [JavaScript APIs][overlay-javascript-apis] and [CSS Environment Variables][overlay-css-env-vars]. Specifying `true` will result in an overlay with default system colors. Default is `false`.