I have the following setup:
cat8->DXE filter->Lhyaudio ocxo switch->etherregen on Antelope audio 10m clock->DXE filter->Emo EN70HD->InnuOs Zenith Mk3->USb->Holo Audio Titanis->Intona Isolator 2.0 Industrial->Antelope Audio Zodiac Platinum on 10m clock. The clock, USB connection and Dac are all powered by Sean Jacobs DC3/4 Lps, the Etherregen by Zerozone 2020 LPS.
Admittedly this is a ridiculous amount of boxes, yet: it took me 3 years to not only figure out the right components but also the sequence.
My principal lessons are as follows: avoid any noise from EMI/RFI/Ground level through galvanic isolation, use shielded cables on digital connections and get the best clock you can afford to control the DAC, ethernet and USB connections. Use digital filters on any clock or ethernet connections. I have not played with optical but worked hard in finding good ethernet and USB cables (0nto cat8 and Intona Reference USB)