As the original poster let me add a few comments (I have also been in dialogue with Cambridge Audio about this).
the CXNv2 does upsample everything to 384KHz sample rate for it’s DAC, as someone with many years experience in recording studios and both professional and consumer, I have expressed to Cambridge Audio that I don’t think this is good practise, and that at the very least the upsampling should be a whole integer of the sample rate, so yes, upsample 48Khz or 96Khz PCM to 384k, but 44.1 or 88.2 or even DSD should be upsampled to 352.8KHz. Cambridge Audio told me the Edge NQ streamer does not up sample and offered no promise of user control of this or of any change on the CXNv2
However they have confirmed as others have written, that the SPDIF digital output is bit transparent up to 24bit 96Khz for the optical and 24bit 192Khz for the coax (so I have connected the Coax)
As others have said, Roon is reporting what the DAC is doing (sample rate conversion and upsampling), and therefore will not show bit transparency with the CXNv2 when you are apparantly achieving just that…
The Cambridge Audio Edge A (a truly amazing amplifier by all measures) has no sample rate indication.
So using the SPDIF out of the CXNv2 to the Edge A I have no idea what PCM rate is in play other than an understanding of what it should be.
That’s the deal, so I just trust my ears, in fact most of the time I use a Chromecast Audio connecting digitally to the Edge A, then Roon reports the bit transparency (to 24b 96K anyhow). To my ears the DSD playback from the CXN to the digital output does not sound very nice.