This extension defines a feature which allows plugin UIs to get a direct handle to an LV2 plugin instance (LV2_Handle), if possible.
Note that the use of this extension by UIs violates the important principle of UI/plugin separation, and is potentially a source of many problems. Accordingly, use of this extension is highly discouraged, and plugins should not expect hosts to support it, since it is often impossible to do so.
To support this feature the host must pass an LV2_Feature struct to the UI instantiate method with URI LV2_INSTANCE_ACCESS_URI and data pointed directly to the LV2_Handle of the plugin instance.