Was/is there an option to treat them on a "cable cooker?"
I think a break-in period is almost universally acknowledged
on electronics, speakers, and cables, isn't it?
Have you ever frozen your cables, or CDs?
Put the cables in a large plastic bag and place in a freezer for two
days. Transfer to the refrigerator for one day. Then,
take them out and remove from plastic bag and place between heavy cloth
or a blanket for one day, to allow them to slowly reach room temperature.
Now, give them a try and let me know if they sound different.
Added steps can include thoroughly cleaning and applying a contact enhancer to the terminals, and gently wiping the cables with a microfiber cloth that has been sprayed with anti-static treatment.
You are only limited by your time, and imagination, right?
