"I guess you do it the way every other person who is not a DAZ pa does it all over the CGI industry"

Then pray tell how exactly "every other person who is not a DAZ PA does it" ?

Seriously, I happily admit that after 15 years of 3D modelling, texturing, shader making, light making, pose making, custom sculpting and custom rigging, I don't have a clue how to ADD MORE REAL DETAIL to G3's low res geometry APART from a displacement or a normal map.

Which are of course both infeasible because they mess with the rigging, cause cloth pokethrough and do not show up in my OpenGL preview.

What are my options, other than to start with a high res mesh?

I'd really like to know, because if there's another method without any of the drawbacks of the previous described methods, I'm puzzled why DAZ keeps their HD tool such a closely guarded secret?