So is that routing legal for the Circle Pacific fare? I got the impression that you could only backtrack between SCL and EZE, other backtracks in South America weren't permitted (having to get back through to SYD from SCL). From the comments I've read the Lan Chile option certainly sounds better than American Airlines, apart from the MRTC if I'm up the back.

I'll keep that option in mind if I take the RTW ticket instead though, certainly sounds more pleasant than a transit in Miami!