"The more definition there is in a base model, the harder it is to morph it out."

Sorry, wrong.
It's easy to smooth a well defined mesh, but it's very hard to get definition in.
M2 has the best muscle definition in Poserdom.
Yet Stephanie 1 is EXACTLY the same mesh.

Besides, this "One size fits all" mantra is what's causing a lot of problems.
You can't have a generic mesh that you just morph into a gazillion of shapes.
Men need different joints than Woman, fat people need different joints than underweight ones, babies need fat rolls, preteens need ribs and knees and shoulderblades sticking out, each figure needs it's own set of face morphs.
It's even hard to get proper ethnic morphs, less alone realistic body types and ages.

Forget about "This figure can be all what YOU want. Just spin a few dials".
If you want truly accurate and realistic meshes, you must specialize.