I think Horney's suggestion is fine - the thread needs to be cut down to the right level, or you'll not be able to fit the filter!
I've got a Golf1 oil cooler kit on the shelf and a sandwich plate kit, but I thought I would try running the crossflow 8V with only the OEM set up to see how I got on. As it happens I haven't experienced any issues with oil temp (it's because I drive so slowly and tend to avoid high revs), so I haven't fitted anything more than the heat exchanger.
I *have* test fitted the sandwich plate and it was fine. It fitted on with a threaded sleeve over the OEM hollow stud. If I was fitting one with no thermostat I would keep the heat-exchanger as it helps warm the oil faster - oil that's too cold will do as much damage as too hot.