Heavy bike lock mount on a carbon frame
In general strapping 1.7 kg of mass to a CFC frame is not a problem. CFC frames are actually quite robust. However, I would be concerned about attaching the case to water bottle mounts. Water bottle mounts, brake mounts etc on CFC frames are constructed with an aluminum insert epoxied in a hole in the CFC. These can work loose if subjected to too much cyclic stress. 

This Hambini YouTube video explains how the inserts work (and how to fix them.

If the case comes with straps, I'd use those instead. Put tape on the frame where the case and straps touch it to stop paint being worn off by movement of the case.