I assume now that I purchased the wrong plugin - but when I went and tested the live demo on your site, it allowed me to copy and paste screen grabs into the body of the post. It does not allow me to do this with the wpForo Embeds addon on my forum.
While can I appreciate that I am at fault - since I can see now that this addon only allows embedding of videos etc. - it is a bit annoying that your live demo allowed me to do it. A little bit misleading perhaps.