A properly built cable truss could eliminate the need for the extra supports under the cantilevered section and serve as a railing as well. I've installed a fair number of truss kits on pipes and it's amazing how much a little cable can stiffen up a flimsey piece of 6" mill pipe.

Here's a rough sketch of what I'm talking about




"The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge." Stephen W. Hawking