@1st post: I tried that at first; I used a vertex group to apply the male slider only to the body, and then made a 2nd target to move the head up. But MT doesn't see vertex groups, and also for some reason in MH, the neck was really long, equivalent to the amount I moved it up to get it out of the torso in MT. Then I created new shape from mix, to copy the effect w/o vertex groups, but MT doesn't save shapekeys that it didn't create. So then I used makeclothes to get a new human, so I could load target as mesh. And then I ran out of time. Away from my PC ATM.
Edit: oh, also, ManuelLab has a more complex skin shader, with multiple texture layers (including subsurface and specularity). Another user tried projecting it to the MH model.