@Bluey
I'm in South Australia and have been using Insight Planner to test my Reefmaster Maps for a few years now. I rechecked the Lowrance site and you are correct (it does say it is unavailable outside the US). It took a bit of looking to find the page that says that.
Originally this software was really "clunky" but the latest version I have (1.3.0.4) seems to work OK. It would be interesting to find out why Navico have made it US only.
Image is from Insight Planner showing a part of the Outer Harbour shipping channel in Adelaide. Blue lines are hand drawn by me from sidescan mosaics and clearly show the dredge marks.