@Rake Rocko - I had a 4 oz addition at the end of the boil and 4 oz in secondary. I had no issues with head retention. I had the same thoughts that you had about it originally but was pleasantly surprised with the nice, long lasting head that the beer had.
Brewed a Belgian chocolate stout not too long ago and boiled 4 oz for 10 minutes then dry-nibbed with 4 oz and got a nice cocao aroma and a bit of flavor as well. Nothing too overpowering but just enough to notice and add some complexity to the brew.