In my experience it is faster to 'down-shift' the eCVT transmission prior to overtaking. The engine revs are already higher, the system will raise them to give the greatest acceleration force, just like any other transmission.
If one simply floors the accelerator in D the system will build revs quite quickly but not as fast as using the S mode paddle shift, as the revs are already raised as one has shifted in preparation of the manoeuvre (the car in full auto mode can't predict what you are planning!)
It is fun to use and as I said previously the 'changes' are really instantaneous, much faster than any other auto I've used in manual mode. PlayStation for the open road 😎