my main gripe is that M3s head has so few morphs (comparatively speaking) to allow for a lot of eccentricities in people's faces.  

Yes, that's why you definitely need to use magnets or otherwise change the mesh. I've found that heavy usage of Mike's Daz morphs can have the effect of making him look slightly odd, too. I think the problem is that each Daz morph only affects one small part of the face - so if you use the "Mouth Raise" morph, the lips climb towards the nose, but the nose doesn't move, and neither does the chin, which leaves him with a tiny philtrum and a huge jaw. To really get a unique look, you need to reshape the whole face/head. 

ZBrush seems to be the morphing weapon of choice these days, so I'd have a play with that if I were you :-)

---

"you are terrifying
and strange and beautiful
something not everyone knows how to love." - Warsan Shire