Materials - How to handle normals and WPO on a landscape

Question. If I use a world-aligned texture on something with WPO , like a rocky-landscape that has a bumpy type effect owing to (heightmap x VertexNormalWS), if the normals are also projected using WorldAlignedNormals (still in tangent-space), do I have to do any additional maths on normals to make them correct? IF I switch to world-aligned, they look slightly ‘better’ in that cracks seems to stand out a bit more when I move dynamic lights around… This tells me my math might be amiss?

I’ve done some research around math-generated waves, gerster-waves, etc and they all seem to account for normals across a warped surface somehow, either through DDX/DDY or some other custom function.

Do I, and how(!), might I account for wrapping/warping normals across a surface that is warped via WPO as derived from a grey-scale height-map x VertexNormalWS?