Hello there. Thank you for reaching out and for sharing this video with us. For additional reference I will post a link where you can learn more about the overview and specifications of the DJI OM 4. Thank you.
There are plenty of videos on YouTube now showing the Zhiyun Smooth 4 in use with the iPhone 11 family. Biggest problem is for the the 11 pro and pro max - the ultra wide angle lens brings the gimbal motor into view. This can be overcome by using the gimbal in flashlight mode.