I have a tricky problem with RBD constraints that I can't quite figure out.

I'm generating hard constraints connecting some packed RBDs to deforming geometry. I can use a SOP Solver to update the @P of the constraint point that's attached to the geometry as it deforms, but I'm not sure of the correct way to update the orientation… I don't what space to transform the constraints into and out of. Simply updating the orientation of those anchor points to match the deforming geometry doesn't work.

I'm attaching a test scene to demonstrate the problem.