Is it possible to use MeshColliders with grid graph?

I’ve been using grid graph for my RTS snice I believe it is signifigantly better for performance (correct me if Im wrong).

However now I need to use MeshColliders on my structures, which does not seem to work. The correct node are no longer set as unwalkable.

What is the intended solution for this scenario?

To be clear, code Im using is (although a normal scan does not work either):

    public void UpdateGridGraph(Bounds bounds)
    {
        var guo = new GraphUpdateObject(bounds);

        guo.updatePhysics = true;
        AstarPath.active.UpdateGraphs(guo);
    }

Would you mind posting a Screenshot?

Yup:

Red circled area should be unwalkable.

Currently thinking the only way is to use box colliders that are only dedicated to updating graph. But hoping Im wrong since that will add some repetetive setup time for each building.