Hi
Thank you for the feature request. We have taken a note of this. Hopefully, it may be available in future.
However, we would like to share that, embedding images from external sources may be a good way to save bandwidth and storage, but this may raise issue on “Google PageSpeed Insight”. Because the image may not be properly optimized or it may have sizing issues (plus if you use a CDN service, those images will be excluded from CDN).
I hope you can understand my point. Let me know your thoughts.