Thanks for the link. We don’t currently do dynamic real time updates to the navmesh. We have had versions similar to what’s described in the link running in our code, but have not yet achieved acceptable performance in real running systems (dozens of objects impacting overlapping meshes while dozens of AI move and pathfind across the changing graph).
Generally characters should be able to reach all destinations on the navigation graph. If your character can’t reach a location, that indicates a problematic graph (possibly generated with a too small walkable radius). You can partially make up for this by setting the AI close enough distance to a higher value.