Yes, all V3 bodymorphs work.
The neck is neither NEA nor V3 geometry, so if you really alter V3´s bodyshape, you might have to make a custom morph with magnets to better blend it in.
But it´s prety flexible as is, and most times you can get by with no extra morphs at all.
I wouldn´t mind a V3 mapped
Posette or NEA, too.
BUT there is a problem, and that is the DAZ EULA.
V2 mapping is "free", so you can use it for other meshes, but V3 mapping is not.
So if you remap
Posette to V3, she becomes a derivate work, and you have to encode her with V3 being the key, even if she contains no V3 mesh.
According to the V3 EULA, you are not allowed to copy V3´s mapping, her shape, and her joint setup.
At least not without encoding the new figure.
stahlratte