I am a Roon newbie, and have my core running on a Synology DS916+ NAS that’s in my home, connected to the world via my Xfinity ISP, which only provides about 40 Mbps up (vs. 800 or so down). I don’t know how that translates into the potential quality of outbound music streaming. I realize this is probably not up to Roon quality, but I have been streaming music from my NAS to my iPhone for years using the DS Audio app on my phone. It sounds fine: not extraordinary; not terrible. It would be great if Roon were accessible remotely, and even better if it could negotiate the optimal quality afforded by the available bandwidth and the D:A on the target device (i.e. my iPhone). But my hunch is that both the bandwidth and the D:A are the quality limiters; not the streaming software itself. Long-winded way of saying that personal streaming is now and has been for years pretty easily available. You can pick up a Synology unit for around $1000 (I believe the 916 I have is no longer in production, replaced by the 920), and it is quite an astonishing device that not only streams music and video, and hosts e-mail, but can also function as a Roon Core. And you don’t need to be an engineer to set one up…
but you might need to be to get Roon over internet working.
FYI if you have moved to DSM7 then ZeroTier is a bit of a challenge…otherwise its an option to consider but the roon client can only connect if there is a wifi connection not over 3G/4G/5G networks