At least it looks like copybar is not changing the actual CMS database content values. Please correct me if I misunderstood the mechanics.
The problem with dynamic replacing would be: 1) search engines get the old text 2) original CMS editing functionality becomes useless for that specific node.
Thanks! Yeah, we're using the CDN to dynamically display your edited content.
When editing an element, we invalidate the cache on the CDN. It may take a minute or 2 to propagate.