Thank you @LGA ,
Interesting that in your setup ENO filter beats Etherregen switch with Ferrum Hypsos psu while streaming Qobuz with K50.
I was not aware of Network Acoustics’ ENO Ethernet Filter. Apparently it comes with optional Ethernet cable in 2 versions, silver and copper with specific sound signatures (that xtra cable you do not use?). ENO runs at only 100mb/s like the Etherregen which I find inconvenient since I mainly buffer albums from a NAS but with live streaming as in your situation that might not be an issue.
I like that you tried many ways to integrate the ER before swapping with ENO. You mention it works very well with Qobuz. Do you also play local files from SSD with K50 and did you by any chance compare with Qobuz and ENO? And playing Qobuz with K50 is in what player - streamer configuration?
I will definitely explore more.
Just found your other post, indeed you do try many devices apparently.