playsinline: A Boolean attribute indicating that the video is to be played "inline", that is within the element's playback area. Note that the absence of this attribute does not imply that the video will always be played in fullscreen.
So I'm not sure that it would appropriate to add it to all of Elementor's videos. It would be nice to have it as a dropdown option, though. You could try submitting a feature request with your use case in a separate issue.