Here's a comparison of the overlayed wire frames. Antonia on top, V2 at the bottom, in case anyone wondered. I think these speak for themselves. If one zooms in quite a bit more on V2, there's actually a visible asymmetry there, but for all practical purposes, this is perfect. Obviously, this is what we'd like to see for Antonia as well.

I still think that in the grand scheme of things, the asymmetry that Poser produces in Antonia is so small that it will only ever matter for really, really tight clothes. But one has to be weary of cumulative effects as Lyrra mentioned. Also, if this effect can be reduced, it can also be amplified, and since we don't know how it happens, we can't be certain that the next edit on the rig will make it really, really bad. So I'd really like to solve this.

By the way, I'll still have to check if the asymmetry gets worse or stays pretty much the same when the figure is posed. I'll use V2 as my benchmark on this.

-- I'm not mad at you, just Westphalian.