Rail Post on CF seat

I am thinking about directly attaching a bike seat post to my seat like Kaycee did here http://www.unicyclist.com/forums/showthread.php?s=&threadid=42519 When I talked to him about it he said there was alot of flex in it. I would be using a CF base so there wouldnt be that much flex but how strong would it be? It looks like with 2 bolts it would be weaker side to side. Also, If i drill more holes in my seat base would it weaken it any? (I already have it drilled for a normal post)