I have ridden a number of times since the recent update on the “Fan Flat” Richmond route.
The cobbles work with road feel and Zwift sound from when they start, through the sprint arch and just up to the sprint marker for the sprint in the other direction. Then, while the cobbles are still on the ground for quite a long distance the Zwift sound of riding on cobbles vanishes for me as does the Tacx NEO road feel.