The description you posted shows compatible with the Impreza/XV for the approach lights (no dimming), if you search the part number J201SSG000 it seems everywhere states it is just 2014 Forester.
Typically with the 10-slot connector you have 9-pins in the car side, 3 for adjust, 2 heat, 2 signal, 2 power folding. SOA could have used the otherwise unused folding wires for the approach light, but there would have to be wiring with the taped up connector inside the mirror for it. Did you see that inside there?