1. Use fixed volume in Roon, bypassing Roon’s software volume control;
2. Disable normalization or ’Volume Leveling’ feature;
3. Disable any sample rate conversion by setting "MAX PCM" in Device Setup; and
4.Turn off the DSP engine in Roon.
Now I have no choice but to use Roon. I replaced my streamer with a ethernet-enabled DAC that exposes a Roon endpoint (or UPnP) but doesn't have streaming capabilities built-in otherwise.
I also do as suggested above. When I had a streamer I tried Qobuz Connect: it was marginally better than using Roon with the above suggestions. I had a problem with the user experience with Qobuz' controller anyway, and went back to using Roon for Qobuz. In any case, my new DAC with Roon sounds better than my old streamer with QC.

