In general, the arguments on here (including my own) are not coming from people who are qualified in the spheres of sound quality and circuit design (in both the audiophile and ethernet domains - they are, after all, two different domains).
Most of us are therefore reliant on what we hear - whether it is on dCS or other Hi-Fi gear - but see my earlier comment about dCS being especially good at eradicating noise from this interface.
Swenson’s experience of designing high-end Hi-Fi circuits, ethernet switches and PHY chips seems relevant and, while he’s not on this forum, appears to know what he is talking about. If you disagree with him, then it would seem to make sense to take it up with him on one of the forums he uses - a link from here, so we can follow the conversation, would be fantastic 
For my part, I will try to refrain from commenting further as repeating what I’ve said previously (in response to a repeated argument) serves no purpose in moving this argument forward.