I should think that the question of whether there will be a single environment encompassing both Dover and Calais could be settled simply by asking MMMMMM to ask Frank_VSTEP.
If such an environment will be in Extremes, it would make little sense to keep it a secret, given that VSTEP is desperate to maintain interest in, and desire for, Extremes until it finally is released.
On the other hand, if such an environment is not to be in Extremes, allowing speculation to raise expectations will, inevitably, lead to bitter disappointment and recriminations.
I, personally, see no pressing need to have both in the same environment if it leads to compromises such as lowered detail in the ports, longer initialization time, lower frame rates, greater demand on available memory, or a foreshortened distance between the ports.