If possible you must try shrinkwrap in Rhino 8 WIP
How did you manage to have such an awful mesh ?
Here a mesh that was healed with Dendro in Grasshopper.
I think you mesh has many problem, it is very far from the origin. And perhaps the scale. So I put the center near the origin ans made a 1000 scale.
With Dendro just use the mesh to volume component with a good voxel size. I choose 1 for the scaled mesh. It is more fast than Shrinkwrap!
