Would I need to make a copy of the mesh's base vertices, uv and normals for PN Triangles?

I am wondering if it would be necessary to make copies of the mesh’s UV’s, Vertices, Normals as a resource for the shader to tessellate properly. I recently loaded a mesh within my program and it has cracks. So, I messed around how much the displacement height should be but I’m still not convinced it’s actually verticies are displaced along the normal because there’s no cracks. However, when I give it a higher displacement height - the cracks show but not when I have minimal displacement map specified.

Would I have to do both calculations inside the shader code and also when I initialize the mesh? I’m all confused in that area.