The other possible fly in the ointment is what SM are going to do, if they do include dual quaternion rigging will the vast majority of Poser users move to G3 in preference to any new figure?

Exactly. If Rendo produced a new figure, SM could sink it by adding support for G3 in future poser versions. Anyway, I imagine the sad tale of Renda is still fresh in Rendo's minds...