How many manufacturers use rivers to fasten the front derailleur hanger to a carbon frame? Is this a kosher procedure? My Focus FD ripped out ! They covered the indentation with a plastic plate bonded to the tube and provided a clamp on derailleur bracket.
My concern is that the bracket doesn't crush the carbon tube. If it was actually round to start with I probably wouldn't worry but they had to build up on one side and I am wondering if the tube will crush, and how will I know if it's happening......

who is "they"? Certainly not the manufacturer of the frame? If it's under warranty of any kind, I'd be all over them about this.

depends on the manufacturer, some will use rivets, some bond in a plate to thread screws into, some use rivnuts. Just dont over tighten the clamp on the derailure.

My SLT developed a crack in the seat tube where the clamp on derailleur was located. It's a little over an inch long, but when I would start to put some pressure onto the frame it would make a very noticeable creaking noise. I am betting that you will notice if something happens.

They, is indeed the manufacturer, Focus , located in San Diego.....So much for German quality engineering....
And now an update: As I feared, today in the middle of my ride and about 20 miles from home a thunking sound and the FD is blocking the pedal! Not while shifting , not while climbing but on plain flat ground! Turns out the derailleur clamp they installed has crushed the tube and pinched it at the clamp bolt!
The frame is shot! I bent back the tip of the derailleur cage with my thumb and limped home on the one down two up I could shift without disturbing anything. When I got home I took the bike to the LBS.......We shall see what Focus wants to do about this, but as I see it they owe me a new frame (bought on father's day) !

To those of you constantly criticizing Chinese frames, heed the warning! The German frames are no great guarantee of quality either......

Someone will be here shortly and recommend an aluminum Cannondale