OK after doing more research it doesn't make sense to use this restriction type as that's about performing U-turns at an intersection, which wasn't the routing issue; OsmAnd was wanting me to perform a U-turn on the way, over a solid white line. Which is different. Will keep reading.

OK thank you I'll update it

I drew the poly and referred to paper map for some of the boundaries for less than 10% of the nodes plus my own on-the-ground survey and GPX data and reused the estuary shorelines and coastline nodes for the rest. Don't think that constitutes breaching copyright.

NSW Government topographic map which I referred to to draw my poly.