I just gave it a quick try with my very limited Poser/Python knowledge and it actually seems to work pretty ok. Its acceptable fast with iterating and the animation looks ok to me even without keyframing every frame.

Well, thats for my very limited figgure and a few animations I have toyed with. I wouldnt swear its an universal solution tho.

The only thing still giving me a hard time are the section modes and the break spine. Ill yet have to figgure out how to retrieve/set them for individual actors.