I am building a free iOS app that plays videos through the official YouTube IFrame Player API inside WKWebView. Users paste a YouTube URL and community members create separate timestamped haptic metadata. During playback, the app reads player.getCurrentTime() and triggers device haptics at those timestamps.

The app does not download, copy, proxy, edit, or rehost YouTube video or audio. YouTube controls, branding, captions, settings, full-screen support, and ads remain available. Videos that disable embedding are not played. The haptic timing data is stored separately from the YouTube content.

The developer policy says an API client must preserve the standard YouTube experience and must not modify, add to, or block standard playback, while overlays such as playback controls may be acceptable when they do not conflict with the player UI.

Does triggering device haptics from current playback time count as modifying or adding to standard playback in a prohibited way? If this architecture is allowed, are there additional IFrame API requirements beyond preserving the player UI, sending the origin/referrer, and respecting embedding availability?