Ha! I suspect there are many of us that got bit by LAN's retiming of many of their flights. (What's up with that, BTW? This was no small change. Of my 6 flights, five moved, and most by an hour or more!)

I, too, have a BA booking on 600. Unfortunately, my connection didn't just shrink, it evaporated: 530 LIM-JFK now leaves at the same moment 600 arrives. I called BA, and they told me the only option was to cancel as there were no award seats on any earlier SCL-LIM flights (in particular 530, to which you also refer). I called LA and they told me to pound sand, a.k.a call BA. I'd be delighted to hear if anyone gets a better resolution, though!

In your case, I wouldn't sweat the 40 min connection in LIM---should be fine as long as your inbound is on time. If not, you can just ride 600 all the way to LAX and hop up to SFO in the morning.

As an aside, anyone know if LA is likely to reinstate 603/604, the SCL-LAX nonstops for the winter season?