I tried that and it didn't work, however, given that Proximas orbit is on the order of a million or two years, so even with the speed auto timestep is going, i'll have to observe for quite a while and 100K sim years on, Proxima shows no sign of slowing down. Then again, acceleration is slowing
Not sure what I did wrong here though.
Not that it matters much anyways because for one, the period is on the order of millions of years and trying to do planetary accretion around that at the same time would just slow US down.
Edit: After 500K years, Proxima went to 3+ light years and even though the velocity slowed slightly, no point in waiting for it to orbit, even if it has an eons long orbit.