I don't think this is the case. The L and N leads are to power the device/relay only and the IN/OUT leads are dry. To power a light using this device, one needs to make it "wet" by connecting IN to L and OUT to the load, as shown in the wiring diagram Zooz provides. The S is indeed line-switched. I believe it is designed this way to simplify a three-way setup for a typical lighting application. You don't have to use S.
In contrast, the ZEN52 double-relay version doesn't have independent inputs so one should assume that the input on the load side of the relay is wired to L internally.
