Hi,
if I use RemeshGrid ProjectToOriginal the Normals seem to be flipped arbitrarily. i tried reverse, facet, polydoctor. nothing works ?

Most likely because you are using thin plate mode
Which will create some thickness around your surface, which when reprojected back will simply be 2 surfaces with opposite normals projected to original object

So maybe make sure your geo is properly enclosedand then use Remesh to Grid in default mode

Ok, thank you very much !