I think the reason there are still jaggies and shimmering remaining in the image is that the instability combined with the low resolution results in some details ending up on completely separate lines, which could well be beyond fixing. The script cleans up most of the lesser instances, which gives a huge improvement in the overall watchability, but the worst aliasing (the interrogation droid and the grid in the Yavin control room come to mind) will probably still be there no matter what. Tis unfortunate, but that's what you get with a source that is mostly crap.

Still, I'd be quite interested in seeing what improvements could come from new anti-aliasing filters.