Similar to cheetah the google robot will also punish duplicate/plagiarized content. So google will decide which website is more likely the original author. One way to do it is what content they discovered first.
So in order not to loose your owns blog organic traffic (steemit will be visited more frequently by google robots as most Wordpress blogs) I suggest a setting where users can set a delay time. Let’s say after publishing on the blog the plugin will post to steemit 12 hours later. Should be easy to implement.
This is from a SEO (search engine optimization) point of view quite relevant. Let me know if you need help or need more information on this issue.
RE: Introducing SteemPress beta, a wordpress plugin for steem