They do work but the require a bit of adjusting...personally this doesn't stop me using Genesis 2 poses on Dawn and Dusk but I always look at a pose as being a starting point and tend to tweak.G2F can pretty well take poses from Dawn. The Studio Dawn, that is.
It would be nice to have poses for a range of models I have converted these ones to Genesis3 also.
Couple of renders using Dawn horse poses to demonstrate the differences.
These are taken from DonAlberts Dawn of the horse poses.
And one using the girl and her horse poses by Morris