Add smart referer spoofing

I know in past Torbutton had this feature and I guess it was removed because of some navigation problems. Correct me if I'm wrong and please explain why is it a good or bad idea implementing this feature.

I'm currently using https://addons.mozilla.org/en-US/firefox/addon/smart-referer/ it's a very little & simple addon but works great. I haven't seen any issue so far