Thanks for jumping into this thread Alex, gives me an opportunity to debunk the EtherREGEN directly rather than “behind Uptone’s back” so to speak 
Disregarding the “Optional clock-input” feature, in Uptone’s white paper John essentially outline two broad issues that the EtherREGEN addresses;
(1) Clock Jitter - the implication being that binary digits flowing through the switch might be mis-interpreted if not clocked properly.
(2) Ground-plane noise carried across the Ethernet port into the DAC, caused by (a) clock-jitter causing phase-noise on the ground plane, and (b) leakage current from power supplies causing AC noise leakage into the Ethernet port.
While there is technical merit to the issue of parasitic AC noise traversing the Ethernet magnetic transformers, it’s quite trivial to prove objectively that any standard off-the-shelf Ethernet switch with no special internal clocking and no special noise-blocking will reproduce totally error-free data streams right to the application end-point without any detriment whatsoever.
An Ethernet switch doesn’t distinguish between bitstreams for music versus Compute applications. Error-free data transmissions occurs across millions of networks Worldwide on a daily basis over standard Ethernet switches, completely debunks all of Upton’s other assertions.
Additionally, everything Uptone addresses in the white paper is only at the physical and Ethernet link layers. In actual fact, music streaming involves the TCP layer above that which provides data stream isolation from any physical/link-layer issues. In the case of Qobuz or Tidal streams for example, these TCP flows have significant packet buffering amongst the network elements involved in the end-to-end delivery. Buffers that add up to 10s-to-100s of milliseconds, and enables the incoming packets at the end-point to be error-corrected, re-assembled, and unpacked into the PCM data that can then be fed to the DAC.
Uptone’s white paper is suggesting that the normal clock-jitter and ground-plane noise that occurs on standard off-the-shelf Ethernet switches have an impact on the end-point TCP payload - that’s complete fantasy which only networking neophytes would believe.
Regardless of whether I fully understand the architecture of the EtherREGEN, the fact remains it cannot reproduces data streams to end-points any better (or worse) than a standard off-the-shelf Ethernet switch. A very simple Ethernet BER/Loopback and iPerf Test would readily trash any assertions otherwise within the digital domain.
And any assertions that EtherREGEN’s impact is in the analog domain has already been debunked; https://www.audiosciencereview.com/forum/index.php?threads/uptone-audio-etherregen-switch-review.10232/
Professional Disclosure: I have an Engineering and Physics background and I work for one of the world’s largest Router/Ethernet Switch manufacturer.