@lmcmalo ,
I expect you would have achieved better results with a $70 USB isolator, a $100 secondary supply, and $50 cable, than the $400 cable, but that is just a guess.
It seems obvious to me that you understand Ethernet at an implementation level, and your comment about the $10 clock shows you have a good grasp of what it takes to make a DAC work.
Unfortunately, there is a lot of inertia in this hobby and I would expect most you will run into on this and similar forums, certainly the heavy posters, are 50+ if not 60+. They grew up with CD players and TOSLINK, back when jitter could be 3-5nsec, and there was no way to properly address it. Ditto for low tap upsampling, poorer on chip analog, synchronous USB, etc. It's 2021, but the mindset is still from 1990ish. The problems that used to exist and have been long solved, are still being brought up like they exist and are just as substantial ... though some implementation appear to be recreating the problems of 1990. There is a whole portion of the industry that survives on keeping that mind set alive, hence you are fighting memory, inertia, and a motivated crowd working to discredit you, or at least people like you.