I don't use HuffDuffer (I've never had time to hunt for stuff episode by episode). But I thought of a potential issue with Overcast's recommendation feature when used with HuffDuffer; I imagine that by default, when a HuffDuffer'ed episode is recommended within Overcast, Overcast might actually feature the episode as linked within the user's HuffDuffer feed instead of from the originating podcast's feed.
Come to think of it, I wonder whether Overcast makes any smart exceptions for HuffDuffer in general.