Displaying YouTube video as an iframe

I use the Divi video module to display YouTube videos, and videos from local sources. Those two video types are handled differently by the module. Local videos are simply embedded as <video>, and the plugin works well with them. However, YouTube videos appear as iframes. Don’t tell me why, but in this case your plugin adds height and width parameters to the iframe, and, as it seems, these are taken from the video’s largest available resolution (res. 1080p results in width=1080).
Apart from generally questioning the sense of this, it would be helpful if one could switch off lazy load for videos *or* iframes, however, you can only do so for both.
In the video module a class name can not be added to the <iframe>, but only to the surrounding <div>, which does not help (I tried this already).
Thanks for any help.