Does Roon affect the sound quality?

Not necessarily so. Users might pick one resampling option or the other (say in Roon) but one is needed anyway so there is always a default one, that can vary from software A to software B. Also, what warrants that implementation details are identical in A and B ? Differences can be heard depending on options and/or operator lengths, in HQplayer. That enables me to be tentatively assertive about what could happen with other software in general without having specifically tried it, like say, Spotify or Tidal…

About my second assertion about measurements of subtle differences, I once made a graph that sums it up, in French in that case. I believe it adresses well the criticism of DaveN about human ear being notoriously : « fickle ? », because the fractional part of of what one can easily measure and hear is not as large as what one can measure but not hear even via a rigorous protocol, or hear but find hard to evidence via a rigorous measurement.

I believe rather that in relative (and not absolute) comparisons, a trained ear is capable of discerning aspects of audio reproduction that one would really struggle to evidence with measurements, and to relate to actual perception. Like the resampling waveform options of HQplayer when they have the same phase, say, from a microphone on a system.
Reciprocally so, one can measure for instance very small amplitude or even phase distorsions on pure tones, that the ear is notoriously weakly sensitive to, probably because there are few pure tone bursts in natural environment that has prevailed in more than 99% of the genetic evolution of our hearing capabilities along with the rest of it !
Regards,
Christian