Having characters walk upside down on nav mesh?

I made a navmesh for a sphere but noticed only a small portion of the top actually had the mesh so navmeshagents navigating the mesh can’t go upside down on the sphere.

Is there a way to ignore the slope angle limit when doing navmesh baking?

Navmeshes must be planar, you need to make a navmesh per face of the sphere and connect them with OffMeshLinks.