I wish we had moving map displays - the only moving our maps do is when you fold them!!
Looking under the goggles at the instruments is not the problem it is when you are trying to mix an instrument and visual (NVG) scan just as you are making the decision to abort that can disorientate - it's that inadvertant IMC moment that gets the heart rate up and going in and out of low cloud can give all sorts of visual illusions.
I think the only problem with using 5000m or 3000m of terrain vis is the ability of the crew to judge it accurately unless there are clear geographical features to use as range markers - I would have thought that there must be many areas of Australia where the terrain is almost featureless. I was given a map by an exchange Aussie pilot of somewhere up the West coast which might as well have been a sheet of sandpaper for all the detail it had on it!!
What is MEL?