I guess you mean the Hide resteemed button when checking someone's blog? That is not really connected to HF 20, that is connected to the web interface. But true, that allows you to hide posts that were just resteemed.
Actually we have a very similar button implemented in Steeve. You can see it when looking at my profile page for example.
Have a nice day, bless you ;-)
Thank you so much and have a great time ahead. 🙂