Even when one one single element of something is rated to be better for some reason, it does not equate to an improvement of the result. Arguing copper to silver is a fool's argument in most cases, not all. Same thing when arguing the heat conductivity of copper over stainless in some uses as in the end of the process the heat exchanged is more than sufficient for the required process. Having the proper gauge copper wire is more important than having any silver. The copper is not holding anything back for our purposes. We can take things to the scientific extreme and argue a lot of BS, but none of the scientific extreme applies here. Proper connections, soldering, and shielding are a much greater value.