I am not entirely sure what you are suggesting, but if Gordon understood you correct in wanting multiple simulations at once, then that is actually something we have considered. Not really to simulate multiverses", but rather to have a real-time comparisons between two sims with slightly different settings. That could be slightly different tolerances, integrator or perhaps gravity.
It would also be interesting to spawn a number of asteroids with ever so slightly different properties for position and velocity and see how their motion will diverge over time. This would be interesting to show how uncertainty about the actual precise properties of near-earth-objects can lead to either a hit or miss in the future.