"I always wonder about the modified possette ... Does anyone know if they are just render and go or if each of the bends involves going into the joint parameters for something specific to the render? Just wondering."

AFAIK all the joint modifications Jim Farris made to his Posette are permanent and ERC controlled, just like those of V3 or V4.
That means the renders show exactly how she bends by herself when you pose her without any additional work.

But by using joint poses it wouldn't be actually hard to even switch joint parameters inbetween poses.
(And do the same for clothing)
Professional studios usally create several different rigs per figure because weightmapping isn't actually that flexible and perfect as some people seem to think.

I prefer to apply my morphbrush fix morphs either  manually or via a pose file because I don't trust an automated system and try to keep the base cr2 as simple as possible, but they could be easily ERC rigged just as well.