I think if you spend at least 24 work hours on the map you could expand the navmesh to the maximum by morphing Terrain (preventing tris clusterfuck), turning overgrowth into staticobjects to remove some of them(reduce navmeshtime), adding here and there some cool stickies, cutting of the combatzone with walls and Melons new method and taadaaa. Fools road and navmesh in each GRID.