Just use the dsg mode that suits your mood. Most of the time I’m in D if commuting, but S transforms the car. It was amazing today on Suffolk B roads but driving down here put it in eco, use acc and it’ll return 42 mpg. Can’t complain.
The thing I find with the Eco/ACC combo is that the ACC stops one of the most "Eco" features, i.e. the car doesn't coast any more. Which i think is stupid