The flange has to be there to bolt it to the body. There is not much material left oncecyou mill a feed port hole in the top of the body. I had to twist the feed neck some to get enough material to tap to bolt the feed neck on with. I should have an update on this very soon.
Threading the feed neck into the body could work but with the material Bing so thin in the center it would be very difficult and probably very hard to install and remove without damaging the threads. I went with the flange style fee deck for its simplicity.