You may or may not know this already. If you do, then please skip this thread. If you don’t, then read on.
You can still make vertex keys in Make human.
I have found this as a quick and very easy way to come up with relative keys for blinking, smiling, talking, etc. When you have your mesh all finished, create a key on the mesh. Then manipulate the mouth, eyes, other parts with the make human sliders. Create another key. Do this until all expressions that you want are keyed in. Then simply save your model as a blender file. TaaaDaaa. Easy and clean relative keys all set up for you in a fraction of the time.