yes, it is about automatic samplerate switching.
“One can Remote Desktop onto the desktop application to control. Yes, a little clunky, but more economical if one already have a pc for that purpose or mostly listen from a local library and only stream on occasion.”
Sure you can. But how do you want to feed HQPlayer with automatic sample rate switching? Remote desktop does not help you with that eiter. Seems you really need hardware to get this automatic switching…arrrgggg 
(Amazon Music has a switch for “exclusive” mode, trying differen virtual cables in that mode. non of those switch sample rate automatically. and still if one virtual cable would switch, you are not in HQPlayer with switching samplerates too…that would be the next challenge…so, i fear hardware…++ maybe you get Amazon to switch samplerate on Windows or Linux?
++Edit; I guess I have to explore this way for Apple Music or Amazon Ultra… Can a local server stream FLAC to Roon? ++ Once you are in Roon, you are in HQP as well…Also Roon´s Squeezebox interface might provide options…? WaveInput plugin - SqueezeboxWiki +++ Whatever. If Apple or Amazon would not be so resistant to access their hires streams, we would not have all of this issues here. …Just my 2 cents on this. Or this one… Home · TheAppgineer/roon-entrypoints Wiki · GitHub