The smoothness is just coming from the smooth preview, will it still be possible to animate as it is now? Or is retopology the only way forward for animation?
Yeah...seam will be distorted...however, you can use a little trick to fix it: Add an edit Poly Modifier between the Unwrap and the MSmooth Modifiers, select all edge and break them. Add a unwrap Modifier on top of MSmooth, open Channel Utilities and copy the Mapping Channel. Delete the edit Poly Modifier and copy the Map…
I have tried everything with my smoothing groups, smoothed, hard, blended, unlocked normals..everything..no flipped normals nothing. This mesh has a rig attached to it as well. It looks fine in Maya.