You said:
As a means to explore music to purchase on CD, the Node, playing Qobuz, may or may not suffice. As a substitute for CDs, I very much doubt it will do.
If your listening skills and system are as good as what you say in this sentence, then I’ll just suggest my ears would agree with yours. My system, including the most important part–the room w/ treatment–shows that CD signals into my DAC have superior transparency, dynamics, and PRaT over streaming local files from my server. Nevermind Spotify or Qobuz...no blind test needed. Streaming is convenience. It can be excellent, but unless you're spending on power quality for the streamer (this is why it seems to me, that there aren't many streamers in the sub-$1,000 range, not many for $1,000, but lots $2,000 and more. Auralic dropped the low end of the market entirely and their Aries G1 and G2 line *start* around $2800, I believe. Providing clean signal and clean power are the main reasons, it seems to me.
Even a very good streamer will likely still fall just short if you’re used to listening to music at the forefront of your attention with CD quality playback. The exception might be if you're upsampling with software like HQPlayer.
If you can hear when a person’s voice sounds like they’re sick during flu season, you surely can hear the difference on a resolving enough system.
Stream to explore, stream to headphones maybe, but buy CDs and play those or local files streamed to your DAC (via a streamer with a LPS) to enjoy the highest quality playback. The LPS is, in my opinion and experience, the most important part, not the sample rate or other distractions. Quality audio is quality power.
Good luck!