I've seen it done on a Scott Spark or Scale and it does look cool. I'm fairly certain it does save a tiny bit of weight, too.
The problem is that you know nothing about the cf lay up of your ISP. If it's able to support a clamp one could guess that it's able of supporting a seatpost head, but you wouldn't know. You'd have to somehow reinforce the holes you drill for sure.
You could try and contact the manufacturer and ask them if it would work or not, but if I were a manufacturer I'd not have an engineer answering my e-mails and if I was answering e-mails for a manufacturer and was not an engineer who knew the part in detail I'd just flat out say "no".
Light-bikes.de has a bunch of very educated people with experience in working with cf and it has an "English section" as well. If you told people what you were up to and to what specific model you wanted to do it to they might be able to give some advice. Maybe someone could even provide a piece of cut off ISP to check out. At the end of the day, if they say it's possible, you'd have some advice from a couple of complete strangers and you pay with your health (and frame) if you trust them, so that's only helping to a point. But if they say it's completely nuts you have one less thing to worry about.
BTW, you do realize that you'll have to stock up on shoes, pedals and saddles, because you won't be able to change those to a different model?
"Nothing compares to the simple pleasures of a bike ride," said John F. Kennedy, a man who had the pleasure of Marilyn Monroe.