Geometry nodes set position and also "stick to normals"

Hi,
Sorry in advanced to spam with this topic.
I am trying to put a blend shape on top of an alembic cache via geometry nodes. My current setup is like this:
https://blenderartists.org/uploads/short-url/73SSfMDxPtXejcQRHsD0QaCmwg4.blend
https://blenderartists.org/uploads/short-url/vc3pVOV1OlXnfyM1Cc9137RMFX9.abc

When trying to take the object normals into account, so the deformation “sticks” to the surface, I lose accurate deformation. If I don’t take normals into account the deformation is in object space, and basically useless in this case.
I’m trying to be able, to fix bad deformations on an alembic chache. Here is my current example:

If anyone could help me to find a solution of having an accurate deformation which sticks to the surface, I would appreciate a lot.

Thanks,
Stefan