>>1019775
I select faces with vertex groups and then use these geonodes to point their normals towards an associated empty. It is really simple but the Set Mesh Normal node was added last month, so it wouldn't have been so simple before. It's basically the flat face technique with extra zones, but I guess the normals can also be animated and don't need extensive preparations and/or baking or transfers.
Sorry for the shit quality screenshot, I use linux.