[Closed] Drilling carbon frame for stealth dropper

So, was looking at dropper posts for my son's (non-stealth) bike and it got me thinking about how easy it would be to just pop a quick hole through the lower part of the seat tube. Surely, such a small hole wouldn't make that much difference, would it...?

Has anyone been brave enough to do this and, if you did, what was the outcome?

(Note: I'm not proposing to pepper the frame with holes - just a single hole to bring the seatpost cable out towards the bottom of the seat tube. The cable will then run externally up the downtube as normal)