Was going to do this mod myself but discovered that Joe at Zpacks would do it for not much more than the materials would cost me. I'm slow as molasses so shipped'er off to Joe and just got it back.
Joe didn't have any of that funky green cuben that the rest of the Hexamid was made with so used the blackish cuben instead. I had him leave the zipper long so I could attach netting around the perimeter, like the Wild Oasis. I also had him change the pitch on the existing beak to steepen it...so the new addition wouldn't stick out too far.
I wanted this mod done to increase the tarps storm worthiness, warmth and privacy. It adds extra room as well.
I haven't weighed it yet. Once I get the netting on and combine it with a .75/oz cuben poncho/groundcloth I'm making, total shelter weight, with stakes, should be around 12oz. I'm stoked to get this system finished and in use!
EDIT: Let me add that Joe is a class act to work with. He is obviously dedicated to customer service. He also threw in a tube of SilNet at no charge. Little details like that make a difference!