I'm not saying the motivation of KB3 and IJ4 would be the same, I'm saying that the visual and stylistic difference between KB1+2 to 3 would be very similar to the visual difference between IJ3 + 4.  Quentin Tarantino couldn't make a movie like he did in 2003 because he's not the same person or artist that he was in 2003.  And to be fair, he could do a story about Nikki but it shouldn't BE Kill Bill 3, it should be a spin-off or independently-identified flick to avoid that comparison.  And while he may want to do the movie and have the actress (which I DO think is cool), there's no guarantee that girl would be any good in the role.