Locking collision RBD centroid for Big Bang uniformity

[MOKANA]

I am building out a Big Bang collision. 

I have a very large sphere that I use as the all encompassing universe. This is a static object. It is the Universe Sphere.  

I then have an RBD that I set the "center" parameter/attribute to the Universe sphere center channel. This sphere serves as the Big Bang, which has been fractured via Vonorni. 

I use a smaller sphere, whose "center" parameter is also set to the Universe Sphere center channel, as the initiator of the collision. 

I set the radius up for the Spheres. 

The Initiator Sphere is key framed with a Uniform Scale of 0 and then the very next frame it is set to 1.  The size of this instantaneous expansion sets the velocity. 

I set the mass of the Initiator Sphere way up and I use a Position node to keep this Sphere for the most part locked down. I set bounce to 0, rotational spin to 0, and friction to 0. 

Over all, these settings, for the most part, keep the Initiator Sphere locked at the center of the Universe Sphere. 

However, I am getting a very slight wobble, before the Initiator Sphere settled down into a perfect center in reference to the Universe Sphere. 

What I am asking is what is the most efficient way to stop the wobble and lock the Initiator Sphere to the center of the Universe Sphere. 

I have looked at Constraints, however, the universe sphere is a static object, not an RBD, so I am thinking constraints will not work. 

I am looking for a very uniform collision across all out ward moving vectors, much like a uniform nuclear detonation. 

Any help would be much appreciated.