Interesting. I always associated cable burn-in to the dielectric, not to the metal conductors - the only scientific evidence of cable burn-in I have ever found was related to noise in Teflon cables. Do you have any explanation for why high voltages transform the copper?
Agreed on dielectric making a difference on burn-in, but I think there is more to it and the metal changes in some way due to current flow. I wish I could explain it, but it's very clear to hear on the cables I mentioned, Audience uses UPOCC copper from what I know and if you compare a basic UPOCC copper cable to audience the audience has less warmth and better clarity, sort of halfway to silver. But it sounds a little off and maybe dull vs UPOCC silver, it's not as good imo. Jorma is better, the result is smoother and sounds more "right". These could pair well with a system that needs warmth, but it does still sacrifice some resolution vs my D4 and DSR silver based cables. It's maybe more resolving vs my D5 but my D5 has better tone I think.
In any case the audible results are night and day, I think it would be possible to zap a basic $50 UPOCC copper cable and come out with something a lot better than it has any right to be for the price. Jorma is big-$ for a copper cable but they are really good and can compete with the best IMO. I certainly can't make a copper cable near as good, but I do look forward to experimenting with a Tesla coil once I have more time. It's on the back burner for now, I gotta get this speaker done...