I think this feature would be a real time saver for anyone looking for help as well as anyone offering help and advice.
Since copy/paste works inside UE4 and it actually is stored as plain text, I think it’s perfectly doable to make a functionality for the forums that would enable to copy-paste blueprints from the editor to the forums. They would then be displayed as graphical nodes, just as in the editor. Next to the image there would be a “copy to clipboard” icon that would allow for quickly pasting the same nodes to one’s editor.
Attaching screenshots from the blueprint editor is not that quick and recreating a BP from an image, especially for someone giving feedback and offering help, is really time consuming and might put off a lot of people.
You already have a special “sketchfab” thingy in the Advanced Editor, so why no Blueprint wrapper?
This would be great for the forums, but obviously some plugin/API that would allow embedding blueprints in any html page would be even better.