You mean "building the strongest possible version of your interlocutor's argument", right?

Yes. Steven Kaas's classic quote: "If you’re interested in being on the right side of disputes, you will refute your opponents’ arguments. But if you’re interested in producing truth, you will fix your opponents’ arguments for them. To win, you must fight not only the creature you encounter; you must fight the most horrible thing that can be constructed from its corpse."

Of course, you don't want to stretch their arguments so much that you're just using silly words. But in my experience humans are way biased towards thinking that the ideas and beliefs of other smart people are significantly less sophisticated than the 'opposing side' wants to give them credit for. It's just human nature. (I mean, have you seen some of smart theists' caricatures of standard atheist arguments? No one knows how to be consistently charitable to anywhere near the right degree.)

It might be worth noting that from everything I've seen, Michael Vassar seems to strongly disagree with Eliezer on the importance of this, and it very much seems to me that to a very large extent the Less Wrong community has inherited what I perceive to be an obvious weakness of Eliezer's style of rationality, though of course it has some upsides in efficiency.