Almandog,
This is an interesting question/concern which I have considered at length in my pursuit for perfection in speaker cables, and I’m glad you bring it up. In my case I use Acoustic Zen Absolute Copper interconnects and Hologram 2’s at the recommendation of Robert Lee, owner of AZ for optimizing my system which includes PASS labs x250.8, XP-20 preamp and among others Focal Scala Utopias. I own both connectors for my 2 sets of Hologram 2 speaker cables, spades on both ends, which are zero copper, and spades with locking banana which are brass. I must say trying to hear the difference between the two is difficult. The zero copper length wires of the 9ft runs of each I feel overrides the small brass terminators on the speaker end in the case of the spade/ banana pair. I don’t hear a bottleneck affecting sound in any way, highs lows detail etc. But I propose to you calling Robert ( his cell number is on their website and he will pick up) and discussing this with him and posting your/his conclusions here, as he is articulate, a perfectionist, engineer and former violinist. It could be very helpful to all.
Best,
janmnov