Yeah, I get not wanting roads everywhere. It's sparked my interest, so I might write some height weighted A* roads in Unity myself, but with a different method. Rather than connecting each node to 2 or 3 neighbour nodes, which can make redundant paths as well as leave two halves entirely disconnected, I'd pick one node to be the primary, eg. the biggest city, then connect every appropriate POI to that, but... any pixel previously set as road are re-weighted to extremely low cost (or just terminate the search) so every new road feeds into the nearest existing road, rather than seeking a specific neighbour POI, so you'd get a branching pattern spreading out from the "main" city. Maybe if a node finds another unconnected node while looking for the connected group, it can add a road there too...