Morphs are easy to use, but as you say magnets are more versatile. Also with magnets you can span the influence across different actors, with morphs you would need to use ERC to do that.

Why not give the end user the option? Have the morphs as injections, and a set of magnets, so the end user can chose which to use.

I have never used bones for this type of thing, so I don't feel I can comment on that option.