Don’t know about OP, personally I will use Aim offset and custom additive animation on top, since Aim offset alone may not be enough for lifelike animations. So it could be perfectly OK to have 4 animations for head movements alone. notably: look back right, look back left, (these two are difficult with just aim offset You have complex neck shoulder movements happening) look left - look right. If it really needs for extreme poses look up and down as well.
If you are making lifelike things, you would/should probably use morphs to fix the neck based on twist. It’s less expensive then blending more animations in additive…
Morphs are there regardless, not enough alone to correct animations, I was speaking of bone rotations themselves. But all this depends on how complex the character model is and how much time needs to be spent on it.