I think that it is not of much use to speculate about what a skater might have done if he or she had lived at a different time and had competed under different rules. It seems sort of moot to try to guess whether Katarina Witt would have had a triple Axel if she had lived thirty years later. Plushenko is the only one who actually did dominate under both systems, from the 2002-03 season to 2005-06.
Chan is an interesting case. He is the master of the CoP. He knows under what rock each tenth of a point is hiding, and he knows how to gather enough of them that it doesn’t really matter about the mistakes. His Elegy exhibition program shows that he is capable of skating beautifully, and his Elegy short program shows that he can switch gears and grab up the CoP points instead.
The reason that I list Yuna Kim alone as a two-fer among active skaters is this. Her CoP programs are 6.0 programs. IMHO her performance of Les Miz at 2013 worlds, just as it was, would have beat any ladies’ LP ever, CoP or 6.0, including herself at 2010 Olympics. Looking at the protocols, she won almost entirely on GOE. Her total GOEs were an insurmountable 16.51, compared to 4.59 for Kostner and 3.66 for Asada.
This is just what 6.0 rewarded, too. Acceptable difficulty and every element done with awe-inspiring perfection. Couple that with satisfactory spins and moves in the field, along with good flow and grace throughout, and Bob’s your uncle. The only 6.0 weakness would be that she didn’t do a triple loop (6.0 was happiest when the skater did the full repertoire of jumps; CoP let’s you omit an element or two and make up the points elsewhere.)
A great 6.0 skater (like Kim) casts a spell of effortlessness, confidence, and mastery, of being totally in command of every detail of the performance. In contrast, CoP point-mongers are often helter-skelter, blowing one element but charging ahead like a bull in a China shop to the next undeterred.