@mike_in_nc I find it difficult to assign a reason for sound signature with ethernet cables as well. In any case, can't say I've heard one. I can understand the cat 8 being inferior as it transfer noise via ground plane. On the other hand, cable itself more impervious to rfi, still can get in connectors.
In my ethernet cable experiments only heard differences in noise floor, I agree Supra only so, so. Settled on Audioquest Vodka, haven't bothered since.
By the way, many of us concerned with galvanic isolation of ethernet, a la fiber conversion or filters of various types.