Just because one app supports those things, doesn't mean another will (or even should) too - all of this also has been brought up several times over the years (I suddenly feel déjà vu, hahaha). It's ultimately up to JRiver if they want to invest development time (which time = money) in pursuing such things. It's their prerogative if they want to pursue such things and from what I've seen Jim say over the years, they're simply not interested in doing so. There are workarounds like on Windows using the WDM driver with apps like Tidal, and that's as good as it's likely going to get, if I had to guess.
Maybe if Amazon came to JRiver and paid them to integrate Amazon Music, it might happen, but after I've seen over the years I wouldn't hold my breath.
Now, for the topic at hand, this has been discussed some recently in other topics. In my opinion audio support in Media Center is the most mature part with many different features. Not counting streaming services and MQA since those don't seem to be on the table, at least in the short term, there's not really much left that could be done in regards to audio except improve existing audio features like they've been doing in regards to DSP. If you have something specific to request, you might do so
in this topic here. In my opinion creating topics like this are kinda pointless, since the app is called JRiver Media Center and it has a focus on ALL multimedia types whether it be audio, video, images, etc. It's not a audio tool or a video tool, it's a media tool.
Bottom line, in my opinion, Media Center already supports bit-perfect audio output. I really don't see how you can get any better than that without applying DSP effects (which then it's not a bit-perfect audio output anymore).
