Chen Lu - now there is a skater who would have struggled a bit with COP, at least on the spins, and also with URs.
Of course, she would have been medaling at lot earlier, imo, if COP had been in place in the early 90s.
There's what skaters did under 6.0, and what they were capable of. I think Kwan could have made the necessary adjustments to the more recent versions of COP. But I don't think Chen could have adjusted. Who knows, maybe I'm selling her short.
Neither would have done well under the 2006 rules, as far as spins are concerned. That version of COP was insane.