Hi, instead of setting the featured image from the media library, is it possible to set it from an external URL directly from the editor? That way I don't have to modify the database entry to the external URL.
This is already present in the wordpress by default, when you click on add media button you can see a insert from url option on the left, refer:
http://prntscr.com/axi36r
Featured image is on the right side panel. There is no option to upload from URL there.
http://prnt.sc/axx2nx
Yes in feature image you cannot set it from the external url.
It is a wordpress default feature and the theme has nothing to do with this feature, so unfortunately we cannot help you with this. Please try contacting the wordpress support forum for this purpose.