I'm betting same technology but different parts. IIRC the Impreza-RS also has 4-wheel steering.
HICAS on the Nissan is usually passive, unless it is labeled "active HICAS". I have seen a picture of an SVX dashboard with the 4WS light lit up. You don't need indicator lights for passive steering sytsems. Ergo, the SVX was available (in Japan?) with active 4WS.
The 4WS has been blamed for the failure of rear wheel bearings on the SVX.
I have spoken to a Kiwi (New Zealander) who swears up and down he got to ride in a 5-speed SVX that was imported used from Japan. He described the interior of my car before seeing it, and I have no reason not to believe him. Must have been a custom conversion.