Cage,

Well, VK's method for moving the origin is not based on ERC, and does not need ERC to work. It just relies on two translate channels for each rot channel that needs its origin moved, a translate channel (lets call it B) after the rot channel determines how far the origin is to be moved, and another translate channel (lets call it A) before the rot channel contains the inverse value and thus restores the origin.

I think it is good news that ERC is not needed, because as I understand it there are problems adding ERC slaving via Python.

Nruddock's chain figure showed the way, but it has a glitch, see image above. So I made a new version of my chain that uses the VK method to adjust the origins. It has two extra channels per actor and no ERC. I'll send you a copy.