Since CFST is as strong as metal, the behavior is expected to be similar. During such conditions steel tubing, drill pipe, and collars have been seen expelled from the well. That will likely happen with CFST too. Will it happen sooner? Not sure, but even if the event fully escalates 50% faster than with metal, the consequences will not be different, only instead of say an hour, it might happen in 30 minutes. Nothing to avert the consequence of such an event can be done in that time frame. Steel pipe, casing, and tubing have been sand-cut in minutes resulting from the extreme velocities of the two mediums together. Similar expectations for CFST.
There is no reason, when looking at other Industries, to believe non-metallic composite is less strong than metallic are. Airplanes are made of carbon fiber (CF), F1 cars are accident impact strengthened with CF. They are all much stronger than metal equivalent material. The unique and extreme forces in an uncontrolled well flow cannot be counteracted by metal or non-metallic composites, they will perform similarly.