That should be possible, it really depends on how you set your expression.
I understand that in Daz3D the shapes are driving everything else, that makes sense probably because of how the software evolved.
If I had to do a similar system in blender, I’d probably start with the rig : I’ll make a rig that can change proportions, and then drives the shapes of the mesh according to that.
Another solution, would be to work with shapes and make an auto-rig that match the mesh proportions, that would be a two step process then . First build the character and then rig it . But that’s maybe not what you want. That would give more a character generator than an adaptable rig.
Have you looked at this ?
and this ?
These look like similar attempt of what you’re trying to acheive, maybe it’s worth checking how they did it !